Answer:
7) a = 60; b = 100
8) c = 20
9) d = 45
Step-by-step explanation:
7)
a + 120 = 180
a = 60
b + 80 = 180
b = 100
8)
5c + 4c = 180
9c = 180
c = 20
9)
3d + d = 180
4d = 180
d = 45
The answer is 69.6 degrees because all of the angles of a triangle always add up to 180 degrees so adding 42 and 68.4 gets 110.4, and then subtracting that from 180 gets 69.9.
There's an app called photomath that would be useful for these kinds of problems!
X = 28
you divide 112 by 4 to get 28