Common Core: High School - Geometry : AA Criterion using Similarity Transformations: CCSS.Math.Content.HSG-SRT.A.3

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Example Questions

Example Question #1 : Aa Criterion Using Similarity Transformations: Ccss.Math.Content.Hsg Srt.A.3

Given the black, green, and purple triangles below, determine which of the triangles are similar?
Hsg.srt.a.3 1

Possible Answers:

All triangles are similar.

The black and green triangle are similar.

The purple and black triangle are similar.

The green and purple triangle are similar.

None of the triangles are similar.

Correct answer:

The black and green triangle are similar.

Explanation:

To determine whether triangles are similar recall what "similar" means and the AA identity. To be "similar" triangles need to have congruent angles. Also recall that all triangles have interior angles that sum to 180 degrees. 

Knowing this, look at the black triangle.

Screen shot 2016 07 15 at 2.33.19 pm

Two angles are given and the third can be calculated.

\(\displaystyle 180^\circ-66^\circ-58^\circ=56^\circ\)

Now, look at the green triangle.

Screen shot 2016 07 15 at 2.33.24 pm

\(\displaystyle 180^\circ-66^\circ-58^\circ=56^\circ\)

Now, look at the purple triangle.

Screen shot 2016 07 15 at 2.33.36 pm

\(\displaystyle 180^\circ-66^\circ-62^\circ=52^\circ\)

Since the black and green triangle have the same angle measurements, they are considered to be similar. The purple triangle only has one angle that is congruent to the other triangles thus, the purple triangle is not similar to either of the other two triangles.

Example Question #2 : Aa Criterion Using Similarity Transformations: Ccss.Math.Content.Hsg Srt.A.3

Given the black, green, and purple triangles below, determine which of the triangles are similar?


Hsg.srt.a.3 2

Possible Answers:

None of the triangles are similar.

All triangles are similar

The green and purple triangles are similar.

The black and green triangle are similar.

The black and purple triangles are similar.

Correct answer:

All triangles are similar

Explanation:

To determine whether triangles are similar recall what "similar" means and the AA criterion. To be "similar" triangles need to have congruent angles. Also recall that all triangles have interior angles that sum to 180 degrees. 

Knowing this, look at the black triangle.

Screen shot 2016 07 15 at 2.33.19 pm

Two angles are given and the third can be calculated.

\(\displaystyle 180^\circ-66^\circ-58^\circ=56^\circ\)

Now, look at the green triangle.

Screen shot 2016 07 15 at 2.33.24 pm

\(\displaystyle 180^\circ-66^\circ-58^\circ=56^\circ\)

Now, look at the purple triangle.

Screen shot 2016 07 18 at 7.19.56 am

\(\displaystyle 180^\circ-66^\circ-56^\circ=58^\circ\)

Since the black and green triangle have the same angle measurements, they are considered to be similar. The purple triangle also has the same angle measurements as the black and green triangles thus, all three triangles are similar.

Example Question #3 : Aa Criterion Using Similarity Transformations: Ccss.Math.Content.Hsg Srt.A.3

Hsg.srt.a.3 3

The \(\displaystyle \bigtriangleup ABC\) above has \(\displaystyle \measuredangle A=26^\circ\). Which of the following triangle measurements would be similar to \(\displaystyle \bigtriangleup ABC\).

Possible Answers:

\(\displaystyle \\\measuredangle G=23^\circ\\\measuredangle H=39^\circ\\ \measuredangle I=118^\circ\)

\(\displaystyle \\\measuredangle G=26^\circ\\\measuredangle H=32^\circ\\ \measuredangle I=118^\circ\)

\(\displaystyle \\\measuredangle G=36^\circ\\\measuredangle H=32^\circ\\ \measuredangle I=118^\circ\)

\(\displaystyle \\\measuredangle G=26^\circ\\\measuredangle H=36^\circ\\ \measuredangle I=118^\circ\)

\(\displaystyle \\\measuredangle G=24^\circ\\\measuredangle H=38^\circ\\ \measuredangle I=118^\circ\)

Correct answer:

\(\displaystyle \\\measuredangle G=26^\circ\\\measuredangle H=36^\circ\\ \measuredangle I=118^\circ\)

Explanation:

To determine whether triangles are similar recall what "similar" means by the AA criterion. To be "similar" triangles need to have congruent angles. Also recall that all triangles have interior angles that sum to 180 degrees. 

\(\displaystyle \bigtriangleup ABC\) is given below. By the figure it is known that \(\displaystyle \measuredangle B=118^\circ\) and by the statement, \(\displaystyle \measuredangle A=26^\circ\). Knowing this information, the measure of the last angle can be calculated.

Hsg.srt.a.3 3

\(\displaystyle 180^\circ-118^\circ-26^\circ=36^\circ\)

Therefore, for a triangle to be similar to \(\displaystyle \bigtriangleup ABC\) by the AA criterion, the triangle must have angle measurements of 26, 36, and 118 degrees. Thus, \(\displaystyle \bigtriangleup GHI\) is a similar triangle.

Example Question #4 : Aa Criterion Using Similarity Transformations: Ccss.Math.Content.Hsg Srt.A.3

Hsg.srt.a.3 3

The \(\displaystyle \bigtriangleup ABC\) above has \(\displaystyle \measuredangle A=36^\circ\). Which of the following triangle measurements would be similar to \(\displaystyle \bigtriangleup ABC\).

Possible Answers:

\(\displaystyle \\\measuredangle G=23^\circ\\\measuredangle H=39^\circ\\ \measuredangle I=118^\circ\)

\(\displaystyle \\\measuredangle G=36^\circ\\\measuredangle H=32^\circ\\ \measuredangle I=118^\circ\)

\(\displaystyle \\\measuredangle G=26^\circ\\\measuredangle H=32^\circ\\ \measuredangle I=118^\circ\)

\(\displaystyle \\\measuredangle G=24^\circ\\\measuredangle H=38^\circ\\ \measuredangle I=118^\circ\)

\(\displaystyle \\\measuredangle G=26^\circ\\\measuredangle H=36^\circ\\ \measuredangle I=118^\circ\)

Correct answer:

\(\displaystyle \\\measuredangle G=26^\circ\\\measuredangle H=36^\circ\\ \measuredangle I=118^\circ\)

Explanation:

To determine whether triangles are similar recall what "similar" means by the AA criterion. To be "similar" triangles need to have congruent angles. Also recall that all triangles have interior angles that sum to 180 degrees. 

\(\displaystyle \bigtriangleup ABC\) is given below. By the figure it is known that \(\displaystyle \measuredangle B=118^\circ\) and by the statement, \(\displaystyle \measuredangle A=36^\circ\). Knowing this information, the measure of the last angle can be calculated.

Hsg.srt.a.3 3

\(\displaystyle 180^\circ-118^\circ-36^\circ=26^\circ\)

Therefore, for a triangle to be similar to \(\displaystyle \bigtriangleup ABC\) by the AA criterion, the triangle must have angle measurements of 26, 36, and 118 degrees. Thus, \(\displaystyle \bigtriangleup GHI\) is a similar triangle.

Example Question #3 : Aa Criterion Using Similarity Transformations: Ccss.Math.Content.Hsg Srt.A.3

Hsg.srt.a.3 5

The \(\displaystyle \bigtriangleup ABC\) above has \(\displaystyle \measuredangle C=13^\circ\). Which of the following triangle measurements would be similar to \(\displaystyle \bigtriangleup ABC\).

Possible Answers:

\(\displaystyle \\\measuredangle G=13^\circ\\\measuredangle H=39^\circ\\ \measuredangle I=118^\circ\)

\(\displaystyle \\\measuredangle G=24^\circ\\\measuredangle H=17^\circ\\ \measuredangle I=118^\circ\)

\(\displaystyle \\\measuredangle G=17^\circ\\\measuredangle H=32^\circ\\ \measuredangle I=131^\circ\)

\(\displaystyle \\\measuredangle G=17^\circ\\\measuredangle H=13^\circ\\ \measuredangle I=150^\circ\)

\(\displaystyle \\\measuredangle G=17^\circ\\\measuredangle H=15^\circ\\ \measuredangle I=148^\circ\)

Correct answer:

\(\displaystyle \\\measuredangle G=17^\circ\\\measuredangle H=13^\circ\\ \measuredangle I=150^\circ\)

Explanation:

To determine whether triangles are similar recall what "similar" means by the AA criterion. To be "similar" triangles need to have congruent angles. Also recall that all triangles have interior angles that sum to 180 degrees. 

\(\displaystyle \bigtriangleup ABC\) is given below. By the figure it is known that \(\displaystyle \measuredangle A=17^\circ\) and by the statement, \(\displaystyle \measuredangle C=13^\circ\). Knowing this information, the measure of the last angle can be calculated.

Hsg.srt.a.3 5

\(\displaystyle 180^\circ-17^\circ-13^\circ=150^\circ\)

Therefore, for a triangle to be similar to \(\displaystyle \bigtriangleup ABC\) by the AA criterion, the triangle must have angle measurements of 17, 13, and 150 degrees. Thus, \(\displaystyle \bigtriangleup GHI\) is a similar triangle.

Example Question #6 : Aa Criterion Using Similarity Transformations: Ccss.Math.Content.Hsg Srt.A.3

Hsg.srt.a.3 5

The \(\displaystyle \bigtriangleup ABC\) above has \(\displaystyle \measuredangle B=139^\circ\). Which of the following triangle measurements would be similar to \(\displaystyle \bigtriangleup ABC\).

Possible Answers:

\(\displaystyle \\\measuredangle G=24^\circ\\\measuredangle H=17^\circ\\ \measuredangle I=118^\circ\)

\(\displaystyle \\\measuredangle G=13^\circ\\\measuredangle H=39^\circ\\ \measuredangle I=118^\circ\)

\(\displaystyle \\\measuredangle G=17^\circ\\\measuredangle H=32^\circ\\ \measuredangle I=139^\circ\)

\(\displaystyle \\\measuredangle G=17^\circ\\\measuredangle H=24^\circ\\ \measuredangle I=139^\circ\)

\(\displaystyle \\\measuredangle G=17^\circ\\\measuredangle H=15^\circ\\ \measuredangle I=148^\circ\)

Correct answer:

\(\displaystyle \\\measuredangle G=17^\circ\\\measuredangle H=24^\circ\\ \measuredangle I=139^\circ\)

Explanation:

To determine whether triangles are similar recall what "similar" means by the AA criterion. To be "similar" triangles need to have congruent angles. Also recall that all triangles have interior angles that sum to 180 degrees. 

\(\displaystyle \bigtriangleup ABC\) is given below. By the figure it is known that \(\displaystyle \measuredangle A=17^\circ\) and by the statement, \(\displaystyle \measuredangle B=139^\circ\). Knowing this information, the measure of the last angle can be calculated.

Hsg.srt.a.3 5

\(\displaystyle 180^\circ-17^\circ-139^\circ=24^\circ\)

Therefore, for a triangle to be similar to \(\displaystyle \bigtriangleup ABC\) by the AA criterion, the triangle must have angle measurements of 17, 24, and 139 degrees. Thus, \(\displaystyle \bigtriangleup GHI\) is a similar triangle.

Example Question #7 : Aa Criterion Using Similarity Transformations: Ccss.Math.Content.Hsg Srt.A.3

Determine whether the statement is true or false.

Hsg.srt.a.3 7

In \(\displaystyle \bigtriangleup ABC\) \(\displaystyle \measuredangle A=73^\circ\)\(\displaystyle \measuredangle B=73^\circ\), and in \(\displaystyle \bigtriangleup JKL\) the \(\displaystyle \measuredangle K=34^\circ\) and \(\displaystyle \measuredangle L=73^\circ\).  \(\displaystyle \bigtriangleup ABC\) and \(\displaystyle \bigtriangleup JKL\) are similar by the AA criterion.

Possible Answers:

True

False

Correct answer:

True

Explanation:

To determine whether triangles are similar recall what "similar" means and the AA identity. To be "similar" triangles need to have congruent angles. Also recall that all triangles have interior angles that sum to 180 degrees. 

Looking at the given triangles and their characteristics, similarity can be identified.

Hsg.srt.a.3 7

In \(\displaystyle \bigtriangleup ABC\) \(\displaystyle \measuredangle A=73^\circ\)\(\displaystyle \measuredangle B=73^\circ\), and in \(\displaystyle \bigtriangleup JKL\) the \(\displaystyle \measuredangle K=34^\circ\) and \(\displaystyle \measuredangle L=73^\circ\).

First calculate the measurement of angle C.

\(\displaystyle 180^\circ-73^\circ-73^\circ=35^\circ\)

Therefore, \(\displaystyle \bigtriangleup ABC\) and \(\displaystyle \bigtriangleup JKL\) are similar by the AA criterion.

Example Question #31 : Similarity, Right Triangles, & Trigonometry

Hsg.srt.a.3 9

The \(\displaystyle \bigtriangleup ABC\) above has \(\displaystyle \measuredangle B=42^\circ\). Which of the following triangle measurements would be similar to \(\displaystyle \bigtriangleup ABC\).

Possible Answers:

\(\displaystyle \\\measuredangle G=92^\circ \\\measuredangle H=40^\circ \\\measuredangle I=48^\circ\)

\(\displaystyle \\\measuredangle G=92^\circ \\\measuredangle H=38^\circ \\\measuredangle I=42^\circ\)

\(\displaystyle \\\measuredangle G=92^\circ \\\measuredangle H=38^\circ \\\measuredangle I=50^\circ\)

\(\displaystyle \\\measuredangle G=92^\circ \\\measuredangle H=42^\circ \\\measuredangle I=46^\circ\)

\(\displaystyle \\\measuredangle G=92^\circ \\\measuredangle H=42^\circ \\\measuredangle I=45^\circ\)

Correct answer:

\(\displaystyle \\\measuredangle G=92^\circ \\\measuredangle H=42^\circ \\\measuredangle I=46^\circ\)

Explanation:

To determine whether triangles are similar recall what "similar" means by the AA criterion. To be "similar" triangles need to have congruent angles. Also recall that all triangles have interior angles that sum to 180 degrees. 

\(\displaystyle \bigtriangleup ABC\) is given below. By the figure it is known that \(\displaystyle \measuredangle A=92^\circ\) and by the statement, \(\displaystyle \measuredangle B=42^\circ\). Knowing this information, the measure of the last angle can be calculated.

Hsg.srt.a.3 9

\(\displaystyle 180^\circ-92^\circ-42^\circ=46^\circ\)

Therefore, for a triangle to be similar to \(\displaystyle \bigtriangleup ABC\) by the AA criterion, the triangle must have angle measurements of 42, 92, and 46 degrees. Thus, \(\displaystyle \bigtriangleup GHI\) is a similar triangle.

Example Question #32 : Similarity, Right Triangles, & Trigonometry

Hsg.srt.a.3 10

Determine which triangles are similar.

Possible Answers:

Triangles A and B are similar.

Triangles B and C are similar.

Triangles C and A are similar.

None of the triangles are similar.

All triangles are similar.

Correct answer:

Triangles A and B are similar.

Explanation:

To determine whether triangles are similar recall what "similar" means and the AA criterion. To be "similar" triangles need to have congruent angles. Also recall that all triangles have interior angles that sum to 180 degrees. 

Knowing this, look at triangle A.

Screen shot 2016 07 19 at 6.10.09 am

Two angles are given and the third can be calculated.

\(\displaystyle 180^\circ-61^\circ-59^\circ=60^\circ\)

Now, look at triangle B.

Screen shot 2016 07 19 at 6.10.15 am

\(\displaystyle 180^\circ-60^\circ-59^\circ=61^\circ\)

Now, look at triangle C.

Screen shot 2016 07 19 at 6.10.25 am

\(\displaystyle 180^\circ-60^\circ-60^\circ=60^\circ\)

Since triangles A and B have the same angle measurements, they are considered to be similar. Triangle C only has one angle that is congruent to the other triangles thus, triangle C is not similar to either of the other two triangles.

Example Question #33 : Similarity, Right Triangles, & Trigonometry

Hsg.srt.a.3 10

Determine which of the triangles are similar.

Possible Answers:

All the triangles are similar.

Triangles B and C are similar.

Triangles A and B are similar.

None of the triangles are similar.

Triangles C and A are similar.

Correct answer:

None of the triangles are similar.

Explanation:

To determine whether triangles are similar recall what "similar" means and the AA criterion. To be "similar" triangles need to have congruent angles. Also recall that all triangles have interior angles that sum to 180 degrees. 

Knowing this, look at triangle A.

Screen shot 2016 07 19 at 6.19.58 am

Two angles are given and the third can be calculated.

\(\displaystyle 180^\circ-64^\circ-59^\circ=57^\circ\)

Now, look at triangle B.

Screen shot 2016 07 19 at 6.20.20 am

\(\displaystyle 180^\circ-60^\circ-59^\circ=61^\circ\)

Now, look at triangle C.

Screen shot 2016 07 19 at 6.20.27 am

\(\displaystyle 180^\circ-60^\circ-64^\circ=56^\circ\)

Since triangles A, B, and C do not have any angles that are congruent, none of these triangles are similar.

All Common Core: High School - Geometry Resources

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