7

Set 4: Triangles

Explanation

Answer: A

In a triangular roof design, two of the angles measure 39° and 84°. What is the measure of the third angle?

A.

57

✓ Correct
B.

67

C.

47

D.

28

Detailed Explanation

Choice A is correct. The sum of angles in a triangle is always 180°. 1. Two known angles: 39° + 84° = 123° Third angle: 180° - 123° = 57° Therefore, the third angle is 57°.

Key Steps:

The correct answer is 57

Why others are wrong:
B: This would give an incorrect result. Choice B is incorrect and may result from a calculation error.
C: This would give an incorrect result. Choice C is incorrect and may result from a calculation error.
D: This would give an incorrect result. Choice D is incorrect and may result from a calculation error.

🎯 Keep Practicing!

Master all sections for your best SAT score