Question

Find the radius of a circle that has circumference 12 more than its diameter.

Answer 1

What's the formula for circumference?

Answer 2

2\[\pi\]r

Answer 3

d=2(pi)r

Answer 4

i mean c=2(pi)r

Answer 5

\[d + 12 = d \pi\] since d = 2r
\[(d + 12)\div d = \pi\]
\[1 + (12 \div d) = \pi\]
\[12 \div d = \pi - 1\]
\[1 \div d = (\pi - 1) \div 12\] invert
\[d = 12 \div (\pi - 1)\]
\[d = 12 \div2.14\]
d = 5.6
C = 5.6 * 3.14 = 17.6 which is 12 more than the diameter of 5.6 (rounded)