Answer:
x=10
Step-by-step explanation:
The two triangles are similar since each triangle is the same shape of right triangle but different sizes. To find x, write a proportion between two equal ratios of side lengths.

Solve by cross multiplying.
28(3x) = 20(4x+2)
84x = 80x + 40
4x = 40
x=10
I'm assuming you mean triangle angles?
If so, all angles add up to 180 so combine them and set them equal to 180.
51+82+5x+2=180
135+5x=180
5x=45
x=9
Answer:
Multiply it by 100%
Step-by-step explanation:
1/2 = 1/2×100% = (1/2×100)% = 50% . . . . . for example
_____
Equivalently, express the ratio with 100 as the denominator.
... 1/2 × 50/50 = 50/100 = 50%
_____
It can be useful to think of "%" as a shorthand way to write "/100".