Question

calcule a area da coroa circular, sabendo que R=7cme r=3 cm

Answer 1

$\'Area= \pi (R^2-r^2) \\ \\ A= \pi (7^2-3^2) \\ \\ A= \pi (49-9 \\ \\ A= \pi 40 \\ \\ \'Area=40 \pi cm^2$