You do the sum(40) subtracted by 8, the answer from that divided by 2 since Erin's two times younger.
40-8=32
32÷2=16
Then if you want to check it you do the opposite and get the same sum(40) so 16×2=32 and 32+8=40
So the radius is 7 inch which is given
Use the formula for the circumference which is 2xpiXradius
2x3.1415x7=44 to nearest integer
It would take 2 pairs of complementary angles because complementary angles have 90 degrees and 180 degrees makes a straight line
You do 60 × 5 = 300, which should be the answer. We can double check this by doing 50 × 6 = 300. So the answer is 300