SAT Math Multiple Choice Practice Question 14: Answer and Explanation

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Question: 14

14.

In this diagram (not drawn to scale), x = 70°, y = 30°. The sum a + b + z equals

A. 40°
B. 90°
C. 100°
D. 120°
E. 180°

Correct Answer: E

Explanation:

E. To be honest, you don't even need to know what x and y equal in this problem. Look at the angle marked c in the diagram below (not drawn to scale). Angles c and z are vertical angles, which means that their measures are equal. Also, angles a, c, and b form a straight line, so a + c + b = 180°. Therefore, a + b + z = 180°. By the way, you can also figure out the actual angle measurements if you want to: a = 30°, b = 70°, and z = 80°.

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