Question

Si el area de la semicorona circular es igual a ...

Answer 1

Respuesta:

b) 4(1 + 3π)

Explicación paso a paso:

A1 - A2 = As

$\frac{\pi r^{2}}{2}-\frac{\pi (5cm)^{2}}{2}=12\pi cm^{2}$

$\frac{\pi r^{2}-25\pi cm^{2}}{2}=12\pi cm^{2}$

πr² - 25πcm² = 12πcm²(2)

πr² - 25πcm² = 24πcm²

πr² = 24πcm² + 25πcm²

πr² = 49πcm²

r² = 49πcm²/π

r² = 49cm²

r = $\sqrt{49cm^{2}}$

r = 7cm

P1 = 2πr1/2 = 7πcm

P2 = 2πr/2 = 5πcm

x = r1 - r2 = 7cm - 5cm = 2cm

Ps = x + x + P1 + P2

Ps = 2cm + 2cm + 7πcm + 5πcm

Ps = 4cm + 12πcm

Ps =  4(1 + 3π)cm