10
lesson pretestMultiple Choice

Pretest

Question 10 • Mathematics II

What is always true about the angles of an isosceles triangle?

Answer
A
All three angles are congruent.
B
The vertex angle is a right angle.
C
The vertex angle is obtuse.
D
At least two of the angles are congruent.

Explanation

An isosceles triangle has at least two congruent sides, and the angles opposite those sides are congruent. So at least two angles are congruent. All three angles need not be equal, and the vertex angle does not have to be right or obtuse.

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