Answer:
vertex angle = 37°
Explanation:
the base angles of an isosceles triangle are congruent (equal )
the sum of the 3 angles in the triangle is 180°
sum the 3 angles, equate to 180 and solve for x
4x + 6 + 10x - 6 + 10x - 6 = 180 ( simplify left side )
24x - 6 = 180 ( add 6 to both sides )
24x = 186 ( divide both sides by 24 )
x = 7.75
Then
vertex angle = 4x + 6 = 4(7.75) + 6 = 31 + 6 = 37°