Question

The measure of the obtuse angle in the isosceles triangle is two and a half times the measure of one of the acute angles. Write and solve a system of linear equations to find the measure of each angle.

An isosceles triangle with interior angles labeled y degrees, x degrees, and x degrees.
System of linear equations

Answer 1

The measures are 40°, 40°, 100°.

Explanation:

x + x + y = 180

y = 2.5x

2x + 2.5x = 180

4.5x = 180

x = 40

y = 2.5x = 2.5(40) = 100

The measures are 40°, 40°, 100°.