Can someone explain to me how to do this?

Step-by-step explanation:

#9 1, 3, 2 are all supplementary lines so the angles have to add up to 180 degrees.

# 10 1, and 2 are supplementary to find angle 3 we figure out how many degrees are in the shape with a formula

(# of sides - 2) * 180, in this case it is 360

the angles are 120, and 90 (given)

angle 2 is 180 - 133 = 47

Those 3 angles add up to 257

The shape needs 360 degrees so 360 - 257 = 103 which is angle 3

#11 1 is supplementary, 2 is 90 (supplementary to 90), 3 is supplementary

This shape must have 540 degrees because it has 5 sides

angle 1 is 180 - 74 = 106

angle 2 is 180 - 90 = 90

We are given 116

angle 4 is 180 - 65 = 115

If we add all these up we get 106 + 90 + 116 + 115 = 427

The total degrees has to be 540 so 540 - 427 = 113

so angle 5 has to be 113 degrees

step-by-step explanation:

what grade level is this? need to know so i can look in my old textbooks!

step-by-step explanation:

infinity is the answer