By looking at the graph and seeing which point crosses the y axis. This point will always have an x coordinate of zero.
Answer:
D.) 8
Step-by-step explanation:
You can use the Pythagorean theorem because this is a right triangle:

a and b are the legs and c is the hypotenuse. The hypotenuse is always the longest side in a right triangle (since it is opposite the biggest angle). The two legs squared have to add up to the hypotenuse squared.
Fill in values:

Simplify exponents:

Isolate the variable. Subtract 225 from both sides:

Find the square root of both sides:

The missing leg length is 8.
(3x-9) +(x+19)+x=180
5x+10=180
-10=-10
5x=170
5 = 5
x=34
2x+(2x+10)+x=180
5x+10=180
-10=-10
5x=170
5 = 5
x=34
yes they are similar