Question

What is the value of y?

Answer 1

D) 55°.

Explanation:

The sum of angles in a triangle add up to 180°.

`y+(y+30)+40=180`

`2y+70=180\\`

Subtract 70 from both sides:

`2y+70-70=180-70`

`2y=110`

Divide both sides by 2:

`(2y)/(2)=(110)/(2)`

`y=55`