# SAT Math Multiple Choice Practice Question 98: Answer and Explanation

### Next steps

- Use your browser's back button to return to your test results.
- Do another SAT math multiple choice practice tests.

**Question: 98**

**10.**

The angle marked a in the drawing above measures

A. 30°

B. 100°

C. 130°

D. 140°

E. 150°

**Correct Answer:** E

**Explanation:**

E. The missing angle in the triangle must be 30°. And because a and this angle make a straight line (180°), a must be 150° (the difference of 180 - 30). In case you're interested, the great world of geometry has also come up with a rule for this sort of problem: The exterior angle of a triangle is always equal to the sum of the two remote interior angles.