Question

The radius of a quarter circle is 1 millimeter. What is the quarter circle's perimeter?

Use 3.14 for ​𝜋.

Answer 1

The perimeter of a quarter circle is equal to a fourth of the circumference of the circle, plus twice the radius

$$P=\dfrac{2\pi r}{4}+2r=(\dfrac{\pi}{2}+2)r$$

$$=(\dfrac{3.14}{2}+2)(1)=3.57(mm)$$