4
practice examMultiple Choice

Practice Exam

Question 4 • Precalculus

Triangle cap m cap n cap p has vertices cap n times open paren 2 comma 2 close paren and cap p times open paren 0 comma negative 2 close paren The triangle is symmetric about the y -axis. What is the approximate measure of the largest angle in the triangle?

Answer
A
60.0 degrees
B
53.1 degrees
C
63.4 degrees
D
83.6 degrees

Explanation

By symmetry, the third vertex is M(−2, 2), the reflection of N(2, 2) across the y-axis. The two equal sides have length √20, and the base MP has length 4. The angle opposite the base has cosine (20 + 20 − 16)/(2 × √20 × √20) = 0.6, so it measures about 53.1°. The two equal base angles are each (180° − 53.1°)/2 ≈ 63.4°, making 63.4 degrees the largest angle.

AI-written and checked against the verified answer.

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