Intermediate Geometry : Quadrilaterals

Study concepts, example questions & explanations for Intermediate Geometry

varsity tutors app store varsity tutors android store

Example Questions

Example Question #81 : Parallelograms

In the figure, the area of the parallelogram is \(\displaystyle 150\). Find the length of the base.

8

Possible Answers:

\(\displaystyle 25\)

\(\displaystyle 10\)

\(\displaystyle 20\)

\(\displaystyle 15\)

Correct answer:

\(\displaystyle 15\)

Explanation:

13

Recall how to find the area of a parallelogram:

\(\displaystyle \text{Area of Parallelogram}=(\text{base})(\text{height})\)

Now, substitute in the area, base, and height values that are given by the question.

\(\displaystyle x(x+5)=150\)

Expand this equation.

\(\displaystyle x^2+5x=150\)

\(\displaystyle x^2+5x-150=0\)

Now factor this equation.

\(\displaystyle (x-10)(x+15)=0\)

Solve for \(\displaystyle x\).

\(\displaystyle x=10, x=-5\)

Since lengths of bases and heights can only be positive, \(\displaystyle x=10\).

Notice that the length of the base is given by the expression \(\displaystyle x+5\). Substitute in the value of \(\displaystyle x\) to find the length of the base.

\(\displaystyle \text{Length of Base}=x+5\)

\(\displaystyle \text{Length of Base}=10+5\)

\(\displaystyle \text{Length of Base}=15\)

Example Question #421 : Intermediate Geometry

In the figure, the area of the parallelogram is \(\displaystyle 500\). Find the length of the base.

8

Possible Answers:

\(\displaystyle 20\)

\(\displaystyle 25\)

\(\displaystyle 15\)

\(\displaystyle 30\)

Correct answer:

\(\displaystyle 25\)

Explanation:

13

Recall how to find the area of a parallelogram:

\(\displaystyle \text{Area of Parallelogram}=(\text{base})(\text{height})\)

Now, substitute in the area, base, and height values that are given by the question.

\(\displaystyle x(x+5)=500\)

Expand this equation.

\(\displaystyle x^2+5x=500\)

\(\displaystyle x^2+5x-500=0\)

Now factor this equation.

\(\displaystyle (x-20)(x+25)=0\)

Solve for \(\displaystyle x\).

\(\displaystyle x=20, x=-25\)

Since lengths of bases and heights can only be positive, \(\displaystyle x=20\).

Notice that the length of the base is given by the expression \(\displaystyle x+5\). Substitute in the value of \(\displaystyle x\) to find the length of the base.

\(\displaystyle \text{Length of Base}=x+5\)

\(\displaystyle \text{Length of Base}=20+5\)

\(\displaystyle \text{Length of Base}=25\)

Example Question #40 : How To Find The Area Of A Parallelogram

In the figure, the area of the parallelogram is \(\displaystyle 164\). Find the length of the base.

9

Possible Answers:

\(\displaystyle 43\)

\(\displaystyle 41\)

\(\displaystyle 39\)

\(\displaystyle 37\)

Correct answer:

\(\displaystyle 41\)

Explanation:

13

Recall how to find the area of a parallelogram:

\(\displaystyle \text{Area of Parallelogram}=(\text{base})(\text{height})\)

Now, substitute in the area, base, and height values that are given by the question.

\(\displaystyle x(x+37)=164\)

Expand this equation.

\(\displaystyle x^2+37x=164\)

\(\displaystyle x^2+37x-164=0\)

Now factor this equation.

\(\displaystyle (x-4)(x+41)=0\)

Solve for \(\displaystyle x\).

\(\displaystyle x=4, x=-41\)

Since lengths of bases and heights can only be positive, \(\displaystyle x=4\).

Notice that the length of the base is given by the expression \(\displaystyle x+37\). Substitute in the value of \(\displaystyle x\) to find the length of the base.

\(\displaystyle \text{Length of Base}=x+37\)

\(\displaystyle \text{Length of Base}=4+37\)

\(\displaystyle \text{Length of Base}=41\)

Example Question #81 : Parallelograms

In the figure, the area of the parallelogram is \(\displaystyle 256\). Find the length of the base.

11

Possible Answers:

\(\displaystyle 32\)

\(\displaystyle 30\)

\(\displaystyle 28\)

\(\displaystyle 38\)

Correct answer:

\(\displaystyle 32\)

Explanation:

13

Recall how to find the area of a parallelogram:

\(\displaystyle \text{Area of Parallelogram}=(\text{base})(\text{height})\)

Now, substitute in the area, base, and height values that are given by the question.

\(\displaystyle x(x+24)=256\)

Expand this equation.

\(\displaystyle x^2+24x=256\)

\(\displaystyle x^2+24x-256=0\)

Now factor this equation.

\(\displaystyle (x-8)(x+32)=0\)

Solve for \(\displaystyle x\).

\(\displaystyle x=8, x=-32\)

Since lengths of bases and heights can only be positive, \(\displaystyle x=8\).

Notice that the length of the base is given by the expression \(\displaystyle x+24\). Substitute in the value of \(\displaystyle x\) to find the length of the base.

\(\displaystyle \text{Length of Base}=x+24\)

\(\displaystyle \text{Length of Base}=8+24\)

\(\displaystyle \text{Length of Base}=32\)

Example Question #82 : Parallelograms

In the figure, the area of the parallelogram is \(\displaystyle 128\). Find the length of the base.

10

Possible Answers:

\(\displaystyle 16\)

\(\displaystyle 12\)

\(\displaystyle 8\)

\(\displaystyle 4\)

Correct answer:

\(\displaystyle 8\)

Explanation:

13

Recall how to find the area of a parallelogram:

\(\displaystyle \text{Area of Parallelogram}=(\text{base})(\text{height})\)

Now, substitute in the area, base, and height values that are given by the question.

\(\displaystyle x(x-8)=128\)

Expand this equation.

\(\displaystyle x^2-8x=128\)

\(\displaystyle x^2-8x-128=0\)

Now factor this equation.

\(\displaystyle (x-16)(x+8)=0\)

Solve for \(\displaystyle x\).

\(\displaystyle x=16, x=-8\)

Since lengths of bases and heights can only be positive, \(\displaystyle x=16\).

Notice that the length of the base is given by the expression \(\displaystyle x-8\). Substitute in the value of \(\displaystyle x\) to find the length of the base.

\(\displaystyle \text{Length of Base}=x-8\)

\(\displaystyle \text{Length of Base}=16-8\)

\(\displaystyle \text{Length of Base}=8\)

Example Question #421 : Plane Geometry

Find the area of the parallelogram.

12

Possible Answers:

\(\displaystyle 169.48\)

\(\displaystyle 184.09\)

\(\displaystyle 199.23\)

\(\displaystyle 186.23\)

Correct answer:

\(\displaystyle 186.23\)

Explanation:

13

Recall how to find the area of a parallelogram:

\(\displaystyle \text{Area}=\text{base}\times\text{height}\)

From the given parallelogram, we will need to use the Pythagorean Theorem to find the length of the height of the parallelogram.

\(\displaystyle \text{Hypotenuse}^2=\text{Triangle base}^2+\text{height}^2\)

\(\displaystyle \text{height}^2=\text{Hypotenuse}^2-\text{Triangle base}^2\)

\(\displaystyle \text{height}=\sqrt{\text{Hypotenuse}^2-\text{Triangle base}^2}\)

Plug in the given values to find the length of the height.

\(\displaystyle \text{height}=\sqrt{13^2-7^2}=\sqrt{169-49}=\sqrt{120}\)

Now, use the height to find the area of the parallelogram.

\(\displaystyle \text{Area}=17\times\sqrt{120}=186.23\)

Remember to round to \(\displaystyle 2\) places after the decimal.

Example Question #421 : Plane Geometry

Find the area of the parallelogram.

1

Possible Answers:

\(\displaystyle 54.99\)

\(\displaystyle 60.31\)

\(\displaystyle 42.19\)

\(\displaystyle 58.29\)

Correct answer:

\(\displaystyle 54.99\)

Explanation:

13

Recall how to find the area of a parallelogram:

\(\displaystyle \text{Area}=\text{base}\times\text{height}\)

From the given parallelogram, we will need to use the Pythagorean Theorem to find the length of the height of the parallelogram.

\(\displaystyle \text{Hypotenuse}^2=\text{Triangle base}^2+\text{height}^2\)

\(\displaystyle \text{height}^2=\text{Hypotenuse}^2-\text{Triangle base}^2\)

\(\displaystyle \text{height}=\sqrt{\text{Hypotenuse}^2-\text{Triangle base}^2}\)

Plug in the given values to find the length of the height.

\(\displaystyle \text{height}=\sqrt{5^2-2^2}=\sqrt{25-4}=\sqrt{21}\)

Now, use the height to find the area of the parallelogram.

\(\displaystyle \text{Area}=12\times\sqrt{21}=54.99\)

Remember to round to \(\displaystyle 2\) places after the decimal.

Example Question #251 : Quadrilaterals

Find the area of the parallelogram.

2

Possible Answers:

\(\displaystyle 189\)

\(\displaystyle 213\)

\(\displaystyle 240\)

\(\displaystyle 256\)

Correct answer:

\(\displaystyle 240\)

Explanation:

13

Recall how to find the area of a parallelogram:

\(\displaystyle \text{Area}=\text{base}\times\text{height}\)

From the given parallelogram, we will need to use the Pythagorean Theorem to find the length of the height of the parallelogram.

\(\displaystyle \text{Hypotenuse}^2=\text{Triangle base}^2+\text{height}^2\)

\(\displaystyle \text{height}^2=\text{Hypotenuse}^2-\text{Triangle base}^2\)

\(\displaystyle \text{height}=\sqrt{\text{Hypotenuse}^2-\text{Triangle base}^2}\)

Plug in the given values to find the length of the height.

\(\displaystyle \text{height}=\sqrt{15^2-9^2}=\sqrt{225-81}=12\)

Now, use the height to find the area of the parallelogram.

\(\displaystyle \text{Area}=12\times20=240\)

Remember to round to \(\displaystyle 2\) places after the decimal.

Example Question #41 : How To Find The Area Of A Parallelogram

Find the area of the parallelogram.

3

Possible Answers:

\(\displaystyle 60.06\)

\(\displaystyle 78.45\)

\(\displaystyle 69.22\)

\(\displaystyle 62.61\)

Correct answer:

\(\displaystyle 62.61\)

Explanation:

13

Recall how to find the area of a parallelogram:

\(\displaystyle \text{Area}=\text{base}\times\text{height}\)

From the given parallelogram, we will need to use the Pythagorean Theorem to find the length of the height of the parallelogram.

\(\displaystyle \text{Hypotenuse}^2=\text{Triangle base}^2+\text{height}^2\)

\(\displaystyle \text{height}^2=\text{Hypotenuse}^2-\text{Triangle base}^2\)

\(\displaystyle \text{height}=\sqrt{\text{Hypotenuse}^2-\text{Triangle base}^2}\)

Plug in the given values to find the length of the height.

\(\displaystyle \text{height}=\sqrt{6^2-4^2}=\sqrt{36-16}=\sqrt{20}\)

Now, use the height to find the area of the parallelogram.

\(\displaystyle \text{Area}=16\times\sqrt{20}=62.61\)

Remember to round to \(\displaystyle 2\) places after the decimal.

Example Question #422 : Plane Geometry

Find the area of the parallelogram.

4

Possible Answers:

\(\displaystyle 95.61\)

\(\displaystyle 82.50\)

\(\displaystyle 93.67\)

\(\displaystyle 90.88\)

Correct answer:

\(\displaystyle 93.67\)

Explanation:

13

Recall how to find the area of a parallelogram:

\(\displaystyle \text{Area}=\text{base}\times\text{height}\)

From the given parallelogram, we will need to use the Pythagorean Theorem to find the length of the height of the parallelogram.

\(\displaystyle \text{Hypotenuse}^2=\text{Triangle base}^2+\text{height}^2\)

\(\displaystyle \text{height}^2=\text{Hypotenuse}^2-\text{Triangle base}^2\)

\(\displaystyle \text{height}=\sqrt{\text{Hypotenuse}^2-\text{Triangle base}^2}\)

Plug in the given values to find the length of the height.

\(\displaystyle \text{height}=\sqrt{8^2-5^2}=\sqrt{64-25}=\sqrt{39}\)

Now, use the height to find the area of the parallelogram.

\(\displaystyle \text{Area}=15\times\sqrt{39}=93.67\)

Remember to round to \(\displaystyle 2\) places after the decimal.

Learning Tools by Varsity Tutors