Question

What is the value of y?
09
O 18
O 3

Answer 1

The answer is 9

Explanation:

First looking at the triangle with the 90 degree sign in it we know that the other angles in that triangle will have to add with 90 to equal 180

So doing the easier way replace 9 with y and do this for the other numbers 3 and 18 to see if the result of (2y+18) and 4y will equal the same number

`(2(9)+18)=36 \\4(9)=36`

`(2(3)+18)=24 \\4(3)=12`

`(2(18)+18)=54 \\4(18)=72`

and because the lines on each triangle represent that those sides are congruent

I hope this because I am only using what I remember from geometry but please let me know if I am wrong