Question

El perímetro de un círculo k tiene 15 cm

Answer 1

$P =2\pi r \\ 15cm = 2\pi r \\ \frac{15cm}{2\pi} = r$

$A = \pi {r}^{2} \\ A = \pi( \frac{15cm}{2\pi} )^{2} \\ A = \pi \frac{225 {cm}^{2} }{4 {\pi}^{2} } \\ A = \frac{225 {cm}^{2} }{4\pi} \\ A = 17.905 {cm}^{2}$