How to find an angle in an acute / obtuse triangle - GRE Quantitative Reasoning
Card 0 of 3
In the figure above, what is the value of angle x?
In the figure above, what is the value of angle x?
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
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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?
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
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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
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
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