What is the value of y? enter your answer in the box. b (5x)° a (2 y+20)° c 40°

y = 40°

Step-by-step explanation:

The triangle in the picture is an isosceles triangle because of the markings on the side (they show that two sides are congruent).

An isosceles triangle not only have a pair of congruent sides, but also have a pair of congruent angles.

So,

5x = 40

Solve for x,

x = 40 ÷ 5

x = 8

5x = 40

5(8) = 40

40 = 40

Now we know the two angles. We then find the last angle containing y.

We know that the total angle measurement of the triangle is 180°.

Set up the equation,

40 + 40 + 2y + 20 = 180

Solve for y,

80 + 2y + 20 = 180

100 + 2y = 180

2y = 180 - 100

2y = 80

y = 80 ÷ 2

y = 40°

i use my brain for prombles like this maybe you could try it

step-by-step explanation: