Question

A jar lid has a diameter of 42 millimeters.What is the circumference of the lid?

Answer 1

circumference of a circle = π x diameter

= π x 42
= 131.946891451
= 132 mm

Answer 2

$\sf{Circumference = \pi \times diameter$

We are given that the diameter = 42 millimeters

$C = \pi \times 42\\\\\boxed{\bf{C = 42\pi \approx 131.95~mm}}$

The circumference of the lid is approximately 131.95 millimeters.