A. 83°
B. 90°
C. 97°
D. cannot be determined

90

Step-by-step explanation:

c is perpendicular to b

That means angles 5,6,7,8 are 90 degrees

a is parallel to c

That means b is perpendicular to a

That means that 1,2,3,4 are 90 degrees

<1 = 90 degrees

the answer is 3/5

step-by-step explanation:

first divide 24 divided by 8 because that is the least common multiple

then divide 40 by 8

then you will get 3/5.