Question

The circumference of a circle is
81 if and only if its radius is 4.
True
False

Answer 1

Answer: True

Explanation:

yes

Answer 2

False

Explanation:

There are at least a couple of ways you can tell this is false.

• The given ratio 81/4 is rational; circumference to radius is irrational.

• The given ratio is about 20; circumference to radius is about 6.