Question

URGENT PLZZZ HELP
Marco wants to put a decorative border around the edge of his circular herb garden. He finds that the distance from the garden's edge to its center is 30 inches. The store only sells the material he needs in 1-foot increments. How many feet of material should Marco buy to completely surround the garden?


plz explain or show work

Answer 1

The area of the shaded portion = 100.48 cm²

Solution:

Radius of the inner circle = 2 cm

Radius of the outer circle = 6 cm

Area of the inner circle = $\pi r^2$

                                      $=3.14 \times 2^2$

Area of the inner circle = 12.56 cm²

Area of the outer circle = $\pi R^2$

                                      $=3.14 \times 6^2$

Area of the outer circle = 113.04 cm²

Area of the shaded portion = Area of the outer circle – Area of the inner circle

                                      = 113.04 cm² – 12.56 cm²

                                      = 100.48 cm²

Hence the area of the shaded portion = 100.48 cm²