How to find an angle in an acute / obtuse triangle - GRE Quantitative Reasoning
Card 1 of 24
In the figure above, what is the value of angle x?
In the figure above, what is the value of angle x?
Tap to reveal answer
To find the top inner angle, recognize that a straight line contains 180o; thus we can subtract 180 – 115 = 65o. Since we are given the other interior angle of 30 degrees, we can add the two we know: 65 + 30 = 95o.
180 - 95 = 85
To find the top inner angle, recognize that a straight line contains 180o; thus we can subtract 180 – 115 = 65o. Since we are given the other interior angle of 30 degrees, we can add the two we know: 65 + 30 = 95o.
180 - 95 = 85
← Didn't Know|Knew It →
The three angles in a triangle measure 3_x_, 4_x_ + 10, and 8_x_ + 20. What is x?
The three angles in a triangle measure 3_x_, 4_x_ + 10, and 8_x_ + 20. What is x?
Tap to reveal answer
We know the angles in a triangle must add up to 180, so we can solve for x.
3_x_ + 4_x_ + 10 + 8_x_ + 20 = 180
15_x_ + 30 = 180
15_x_ = 150
x = 10
We know the angles in a triangle must add up to 180, so we can solve for x.
3_x_ + 4_x_ + 10 + 8_x_ + 20 = 180
15_x_ + 30 = 180
15_x_ = 150
x = 10
← Didn't Know|Knew It →
In triangle ABC, AB=6, AC=3, and BC=4.
Quantity A Quantity B
angle C the sum of angle A and angle B
In triangle ABC, AB=6, AC=3, and BC=4.
Quantity A Quantity B
angle C the sum of angle A and angle B
Tap to reveal answer
The given triangle is obtuse. Thus, angle 
is greater than 90 degrees. A triangle has a sum of 180 degrees, so angle 
+ angle 
+ angle 
= 180. Since angle C is greater than 90 then angle 
+ angle 
must be less than 90 and it follows that Quantity A is greater.
The given triangle is obtuse. Thus, angle
← Didn't Know|Knew It →
In the figure above, what is the value of angle x?
In the figure above, what is the value of angle x?
Tap to reveal answer
To find the top inner angle, recognize that a straight line contains 180o; thus we can subtract 180 – 115 = 65o. Since we are given the other interior angle of 30 degrees, we can add the two we know: 65 + 30 = 95o.
180 - 95 = 85
To find the top inner angle, recognize that a straight line contains 180o; thus we can subtract 180 – 115 = 65o. Since we are given the other interior angle of 30 degrees, we can add the two we know: 65 + 30 = 95o.
180 - 95 = 85
← Didn't Know|Knew It →
The three angles in a triangle measure 3_x_, 4_x_ + 10, and 8_x_ + 20. What is x?
The three angles in a triangle measure 3_x_, 4_x_ + 10, and 8_x_ + 20. What is x?
Tap to reveal answer
We know the angles in a triangle must add up to 180, so we can solve for x.
3_x_ + 4_x_ + 10 + 8_x_ + 20 = 180
15_x_ + 30 = 180
15_x_ = 150
x = 10
We know the angles in a triangle must add up to 180, so we can solve for x.
3_x_ + 4_x_ + 10 + 8_x_ + 20 = 180
15_x_ + 30 = 180
15_x_ = 150
x = 10
← Didn't Know|Knew It →
In triangle ABC, AB=6, AC=3, and BC=4.
Quantity A Quantity B
angle C the sum of angle A and angle B
In triangle ABC, AB=6, AC=3, and BC=4.
Quantity A Quantity B
angle C the sum of angle A and angle B
Tap to reveal answer
The given triangle is obtuse. Thus, angle is greater than 90 degrees. A triangle has a sum of 180 degrees, so angle + angle + angle = 180. Since angle C is greater than 90 then angle + angle must be less than 90 and it follows that Quantity A is greater.
The given triangle is obtuse. Thus, angle
← Didn't Know|Knew It →
In the figure above, what is the value of angle x?
In the figure above, what is the value of angle x?
Tap to reveal answer
To find the top inner angle, recognize that a straight line contains 180o; thus we can subtract 180 – 115 = 65o. Since we are given the other interior angle of 30 degrees, we can add the two we know: 65 + 30 = 95o.
180 - 95 = 85
To find the top inner angle, recognize that a straight line contains 180o; thus we can subtract 180 – 115 = 65o. Since we are given the other interior angle of 30 degrees, we can add the two we know: 65 + 30 = 95o.
180 - 95 = 85
← Didn't Know|Knew It →
The three angles in a triangle measure 3_x_, 4_x_ + 10, and 8_x_ + 20. What is x?
The three angles in a triangle measure 3_x_, 4_x_ + 10, and 8_x_ + 20. What is x?
Tap to reveal answer
We know the angles in a triangle must add up to 180, so we can solve for x.
3_x_ + 4_x_ + 10 + 8_x_ + 20 = 180
15_x_ + 30 = 180
15_x_ = 150
x = 10
We know the angles in a triangle must add up to 180, so we can solve for x.
3_x_ + 4_x_ + 10 + 8_x_ + 20 = 180
15_x_ + 30 = 180
15_x_ = 150
x = 10
← Didn't Know|Knew It →
In triangle ABC, AB=6, AC=3, and BC=4.
Quantity A Quantity B
angle C the sum of angle A and angle B
In triangle ABC, AB=6, AC=3, and BC=4.
Quantity A Quantity B
angle C the sum of angle A and angle B
Tap to reveal answer
The given triangle is obtuse. Thus, angle is greater than 90 degrees. A triangle has a sum of 180 degrees, so angle + angle + angle = 180. Since angle C is greater than 90 then angle + angle must be less than 90 and it follows that Quantity A is greater.
The given triangle is obtuse. Thus, angle
← Didn't Know|Knew It →
In the figure above, what is the value of angle x?
In the figure above, what is the value of angle x?
Tap to reveal answer
To find the top inner angle, recognize that a straight line contains 180o; thus we can subtract 180 – 115 = 65o. Since we are given the other interior angle of 30 degrees, we can add the two we know: 65 + 30 = 95o.
180 - 95 = 85
To find the top inner angle, recognize that a straight line contains 180o; thus we can subtract 180 – 115 = 65o. Since we are given the other interior angle of 30 degrees, we can add the two we know: 65 + 30 = 95o.
180 - 95 = 85
← Didn't Know|Knew It →
The three angles in a triangle measure 3_x_, 4_x_ + 10, and 8_x_ + 20. What is x?
The three angles in a triangle measure 3_x_, 4_x_ + 10, and 8_x_ + 20. What is x?
Tap to reveal answer
We know the angles in a triangle must add up to 180, so we can solve for x.
3_x_ + 4_x_ + 10 + 8_x_ + 20 = 180
15_x_ + 30 = 180
15_x_ = 150
x = 10
We know the angles in a triangle must add up to 180, so we can solve for x.
3_x_ + 4_x_ + 10 + 8_x_ + 20 = 180
15_x_ + 30 = 180
15_x_ = 150
x = 10
← Didn't Know|Knew It →
In triangle ABC, AB=6, AC=3, and BC=4.
Quantity A Quantity B
angle C the sum of angle A and angle B
In triangle ABC, AB=6, AC=3, and BC=4.
Quantity A Quantity B
angle C the sum of angle A and angle B
Tap to reveal answer
The given triangle is obtuse. Thus, angle is greater than 90 degrees. A triangle has a sum of 180 degrees, so angle + angle + angle = 180. Since angle C is greater than 90 then angle + angle must be less than 90 and it follows that Quantity A is greater.
The given triangle is obtuse. Thus, angle
← Didn't Know|Knew It →
In the figure above, what is the value of angle x?
In the figure above, what is the value of angle x?
Tap to reveal answer
To find the top inner angle, recognize that a straight line contains 180o; thus we can subtract 180 – 115 = 65o. Since we are given the other interior angle of 30 degrees, we can add the two we know: 65 + 30 = 95o.
180 - 95 = 85
To find the top inner angle, recognize that a straight line contains 180o; thus we can subtract 180 – 115 = 65o. Since we are given the other interior angle of 30 degrees, we can add the two we know: 65 + 30 = 95o.
180 - 95 = 85
← Didn't Know|Knew It →
The three angles in a triangle measure 3_x_, 4_x_ + 10, and 8_x_ + 20. What is x?
The three angles in a triangle measure 3_x_, 4_x_ + 10, and 8_x_ + 20. What is x?
Tap to reveal answer
We know the angles in a triangle must add up to 180, so we can solve for x.
3_x_ + 4_x_ + 10 + 8_x_ + 20 = 180
15_x_ + 30 = 180
15_x_ = 150
x = 10
We know the angles in a triangle must add up to 180, so we can solve for x.
3_x_ + 4_x_ + 10 + 8_x_ + 20 = 180
15_x_ + 30 = 180
15_x_ = 150
x = 10
← Didn't Know|Knew It →
In triangle ABC, AB=6, AC=3, and BC=4.
Quantity A Quantity B
angle C the sum of angle A and angle B
In triangle ABC, AB=6, AC=3, and BC=4.
Quantity A Quantity B
angle C the sum of angle A and angle B
Tap to reveal answer
The given triangle is obtuse. Thus, angle is greater than 90 degrees. A triangle has a sum of 180 degrees, so angle + angle + angle = 180. Since angle C is greater than 90 then angle + angle must be less than 90 and it follows that Quantity A is greater.
The given triangle is obtuse. Thus, angle
← Didn't Know|Knew It →
In the figure above, what is the value of angle x?
In the figure above, what is the value of angle x?
Tap to reveal answer
To find the top inner angle, recognize that a straight line contains 180o; thus we can subtract 180 – 115 = 65o. Since we are given the other interior angle of 30 degrees, we can add the two we know: 65 + 30 = 95o.
180 - 95 = 85
To find the top inner angle, recognize that a straight line contains 180o; thus we can subtract 180 – 115 = 65o. Since we are given the other interior angle of 30 degrees, we can add the two we know: 65 + 30 = 95o.
180 - 95 = 85
← Didn't Know|Knew It →
The three angles in a triangle measure 3_x_, 4_x_ + 10, and 8_x_ + 20. What is x?
The three angles in a triangle measure 3_x_, 4_x_ + 10, and 8_x_ + 20. What is x?
Tap to reveal answer
We know the angles in a triangle must add up to 180, so we can solve for x.
3_x_ + 4_x_ + 10 + 8_x_ + 20 = 180
15_x_ + 30 = 180
15_x_ = 150
x = 10
We know the angles in a triangle must add up to 180, so we can solve for x.
3_x_ + 4_x_ + 10 + 8_x_ + 20 = 180
15_x_ + 30 = 180
15_x_ = 150
x = 10
← Didn't Know|Knew It →
In triangle ABC, AB=6, AC=3, and BC=4.
Quantity A Quantity B
angle C the sum of angle A and angle B
In triangle ABC, AB=6, AC=3, and BC=4.
Quantity A Quantity B
angle C the sum of angle A and angle B
Tap to reveal answer
The given triangle is obtuse. Thus, angle is greater than 90 degrees. A triangle has a sum of 180 degrees, so angle + angle + angle = 180. Since angle C is greater than 90 then angle + angle must be less than 90 and it follows that Quantity A is greater.
The given triangle is obtuse. Thus, angle
← Didn't Know|Knew It →
In the figure above, what is the value of angle x?
In the figure above, what is the value of angle x?
Tap to reveal answer
To find the top inner angle, recognize that a straight line contains 180o; thus we can subtract 180 – 115 = 65o. Since we are given the other interior angle of 30 degrees, we can add the two we know: 65 + 30 = 95o.
180 - 95 = 85
To find the top inner angle, recognize that a straight line contains 180o; thus we can subtract 180 – 115 = 65o. Since we are given the other interior angle of 30 degrees, we can add the two we know: 65 + 30 = 95o.
180 - 95 = 85
← Didn't Know|Knew It →
The three angles in a triangle measure 3_x_, 4_x_ + 10, and 8_x_ + 20. What is x?
The three angles in a triangle measure 3_x_, 4_x_ + 10, and 8_x_ + 20. What is x?
Tap to reveal answer
We know the angles in a triangle must add up to 180, so we can solve for x.
3_x_ + 4_x_ + 10 + 8_x_ + 20 = 180
15_x_ + 30 = 180
15_x_ = 150
x = 10
We know the angles in a triangle must add up to 180, so we can solve for x.
3_x_ + 4_x_ + 10 + 8_x_ + 20 = 180
15_x_ + 30 = 180
15_x_ = 150
x = 10
← Didn't Know|Knew It →