Question

in an isosceles triangle, the base angle measure 65 degree. which of the following expressions is a way to calculate the measure of the third angle .(a) 180+65 ( b) 180-65 (c) 180+2(65)

Answer 1

An Isosceles triangle has 2 sides of equal length . The base angles of an isosceles triangles are equal. The total angle of a triangle is equals to 180 degree's. The third angle can be found below

$180^{\circ}-2(65^{\circ})$

Note each of the base angle is 65 degrees. Th sum of the 2 base angles will be 2(65) = 130 degree's.