AMC 8 Geometry & Measurement

Question 1

What is the area of a triangle with base 10 and height 6?

Accepted Answer

30

Answer

Area = ½ × base × height = ½ × 10 × 6 = 30.

Question 2

A rectangle has perimeter 24 and length 8. What is its area?

Accepted Answer

32

Answer

Using P = 2(l + w): 24 = 2(8 + w), so w = 4, and area = 8 × 4 = 32.

Question 3

What is the measure of each interior angle of a regular hexagon?

Accepted Answer

120°

Answer

A hexagon's interior angles sum to (6−2)×180° = 720°, so each angle = 720°/6 = 120°.

Question 4

Two angles of a triangle are 55° and 75°. What is the third angle?

Accepted Answer

50°

Answer

The angles sum to 180°, so the third angle = 180° − 55° − 75° = 50°.

Question 5

A square has area 144. What is its perimeter?

Accepted Answer

48

Answer

Side = √144 = 12, so perimeter = 4 × 12 = 48.

AMC 8 - American Mathematics Competition 8 Practice Test