Question

An exterior angle of a triangle is 105and its interior opposite angles are equal to each other. find the measure of each angle of triangle

Answer 1

$180 - 105 = 75 \\ \\ 75 + 75 + x = 180 \\ \\ 140 + x = 180 \\ \\ x = 180 - 140 = 40$
all its angles are 75°,75°,40°

Answer 2

180°-105°=75° (using exterior angle theorem)
as the opposite angles are equal to each other,
then,
75°+75°+ vertex angle =180°(angle sum property of triangle)
vertex angle =30°
so angles of the triangle are
75°,75°,30°