Question

Below is the justification for the formula for area of a circle. Which word, when placed in the blank, best completes this argument?

Answer 1

B half the circumstance pi

Answer 2

B half the circumference or pi r

Explanation:

The base of the parallelogram is pi r

To form the parallelogram the triangles are removed from the bottom half of the circle and moved to flip the gaps in the top half.