Answer:
it depends what level math you are in, there are two answers, if it asks for two answers then the two answers are 2 and -2 if it only asks for one answer then put 2
Step-by-step explanation:
check the picture below.
so it has a base of 18x18 and a height of that much.

X=5
Work:
y=2x-10
4x=2x-10
2x=10, then divide 2x on each side
x=5
If the original angle is x degrees then its supplement is 180 - x degrees.
we have the equation:-
180 - x = 3x + 20
160 = 4x
x = 40
The original angle is 40 degrees and its supplement is 140 degrees