9

Set 3: Triangles (Beginner)

Explanation

Answer: D

PROBLEM

A triangle has angles of 51 degrees and 63 degrees. What is the third angle?

A triangle has angles of 51 degrees and 63 degrees. What is the third angle?

A.

69

B.

65

C.

64

D.

66

✓ Correct

Detailed Explanation

Choice D is the best answer. Third angle = 180 - 51 - 63 = 66 degrees

Why others are wrong:
A: 69 is incorrect because it does not satisfy the equation.
B: 65 is incorrect because it does not satisfy the equation.
C: 64 is incorrect because it does not satisfy the equation.