Question

What is the value of y?



Enter your answer in the box.

Answer 1

The value of y = 40.

5x = 40
x = 8

180 = 40 + 40 + (2y + 20)
40 = y

Answer 2

Hence, the value of y is:

40

Explanation:

We know that angle opposite to equal sides are equal

In given ΔABC we have:

AB=AC

this means that:

∠B=∠C

Hence,

5x=40

on dividing both side of the equation by 5 we get:

x=8

Hence, we get:

∠B=5x=5×8=40°

i.e. ∠B=40°

Also we know that sum of all the angles of a triangle is 180°.

i.e.

∠A+∠B+∠C=180°

Hence,

2y+20+40+40=180

⇒ 2y+100=180

⇒ 2y=180-100

⇒ 2y=80

On dividing both side of the equation by 2 we obtain:

y=40

Hence, the value of y is:

40