Answer:
y = 5
Step-by-step explanation:
Since this is an isosceles triangle, Angle B and Angle C are equivalent. We can use this to find x
3x = 75
x = 25
Angles in a triangle add up to 180, so knowing the measure of Angle B and Angle C, we can find the measure of Angle A
Angle A = 180-(75+75)
Angle A = 180-150
Angle A = 30
We know Angle A = 4y+10
4y + 10 = 30
4y = 20
y = 5
