Question

a certain triangle has two 45° angles. what type of triangle is it?
a. right isosceles
b. acute scalene
c. acute isosceles
d. right scalene

Explanation:

Step1: Recall angle - sum property of a triangle

The sum of the interior angles of a triangle is 180°. Let the three angles of the triangle be \(A\), \(B\), and \(C\). Given \(A = B=45^{\circ}\). Then \(C=180-(45 + 45)=90^{\circ}\).

Step2: Recall triangle - type definitions

A triangle with two equal angles is an isosceles triangle. Since two angles are 45° each, it is isosceles. A triangle with one 90° angle is a right - triangle.

Answer:

A. Right isosceles