Let's use Priya as an example again. The number of hairs per square cm varies from person to person, but Priya has approximately 150 hairs per square cm. She measures the diameter of her scalp from front to back and ear to ear and she finds that it is about 28cm in both directions. Her head is round so that makes her think that she could use the area of a circle to estimate how many total hairs she has on her head.

a. What is the area of Priya's scalp?≈
≈
cm2

b. About how many strands of hair are on Priya's head? ≈
≈
strands of hair