Question

What is the measure of a base angle of an isosceles triangle if the measure of the vertex angle is 38 and the two congruent sides each measure 21 units

Answer 1

To find the measure of a base angle in an isosceles triangle with a vertex angle of 38 degrees, subtract the vertex angle from 180 degrees and divide by 2, resulting in each base angle measuring 71 degrees.

Step-by-step explanation:

The measure of each base angle in an isosceles triangle can be found using the fact that the sum of all angles in any triangle is 180 degrees. Given that the vertex angle is 38 degrees, the sum of the two base angles would be 180 degrees - 38 degrees, which equals 142 degrees. Since the triangle is isosceles, the two base angles are congruent, meaning they have the same measure. To find the measure of one base angle, we divide 142 degrees by 2. Therefore, each base angle measures 71 degrees.

Answer 2

bearing in mind that an isosceles triangle has twin sides, and coming out of the vertex they make twin angles at the base, check the picture below.