Question

A triangle shown with two sides each measure 21. The measure between the two sides is 38 degrees. One of the other base angles is labeled x degrees. What is the value of x?

Answer 1

71

Explanation:

180-38=142

142/2=71

Answer 2

71

Explanation:

When a triangle have two sides with the same measure, in this case 21, it is an isosceles triangle.

An isosceles triangle has special properties, including two angles that are the same. Those two angles are not formed by the two equal sides.

x is one of the angles that are equal to another in the triangle.

All triangles have angles that total to 180°.

Since we know one angle is 38 and two other angles are equal:

180 = 38 + 2x

Isolate x to solve for the missing angle.

142 = 2x

x = 71

Therefore x is 71 degrees.