# GRE Math : How to find the area of a right triangle

## Example Questions

### Example Question #1 : Right Triangles

Quantitative Comparison

Column A

Area

Column B

Perimeter




Cannot be determined

Column B is greater

Column A is greater

Column A and B are equal

Column A and B are equal

Explanation:

To find the perimeter, add up the sides, here 5 + 12 + 13 = 30. To find the area, multiply the two legs together and divide by 2, here (5 * 12)/2 = 30.

### Example Question #91 : Geometry

Given triangle ACE where B is the midpoint of AC, what is the area of triangle ABD?

24

48

72

96

24

Explanation:

If B is a midpoint of AC, then we know AB is 12. Moreover, triangles ACE and ABD share angle DAB and have right angles which makes them similar triangles. Thus, their sides will all be proportional, and BD is 4. 1/2bh gives us 1/* 12 * 4, or 24.

### Example Question #92 : Geometry

What is the area of a right triangle with hypotenuse of 13 and base of 12?

156

60

78

30

25

30

Explanation:

Area = 1/2(base)(height). You could use Pythagorean theorem to find the height or, if you know the special right triangles, recognize the 5-12-13. The area = 1/2(12)(5) = 30.

### Example Question #1 : Right Triangles

Quantitative Comparison

Quantity A: the area of a right triangle with sides 10, 24, 26

Quantity B: twice the area of a right triangle with sides 5, 12, 13

Quantity A is greater.

The two quantities are equal.

The relationship cannot be determined from the information given.

Quantity B is greater.

Quantity A is greater.

Explanation:

Quantity A: area = base * height / 2 = 10 * 24 / 2 = 120

Quantity B: 2 * area = 2 * base * height / 2 = base * height = 5 * 12 = 60

Therefore Quantity A is greater.

### Example Question #42 : Triangles

Quantitative Comparison

Quantity A: The area of a triangle with a height of 6 and a base of 7

Quantity B: Half the area of a trapezoid with a height of 6, a base of 6, and another base of 10

The relationship cannot be determined from the information given.

Quantity A is greater.

The two quantities are equal.

Quantity B is greater.

Quantity B is greater.

Explanation:

Quantity A: Area = 1/2 * b * h = 1/2 * 6 * 7 = 42/2 = 21

Quantity B: Area = 1/2 * (b1 + b2) * h = 1/2 * (6 + 10) * 6 = 48

Half of the area = 48/2 = 24

Quantity B is greater.

### Example Question #2 : How To Find The Area Of A Right Triangle

The radius of the circle is 2. What is the area of the shaded equilateral triangle?