Question

determine a área do circulo inscrito a um triângulo equilátero de lado 12 cm ? tem que dar 12π cm !​

Answer 1

$\large\boxed{\begin{array}{l}\underline{\rm C\acute alculo~da~altura~do~tri\hat angulo~equil\acute atero:}\\\sf h=\dfrac{12\sqrt{3}}{2}=6\sqrt{3}\\\sf r=\dfrac{1}{3}\cdot h\\\\\sf r=\dfrac{1}{3}\cdot 6\sqrt{3}\\\\\sf r=2\sqrt{3}\\\\\sf A=\pi\cdot r^2\\\\\sf A=\pi\cdot(2\sqrt{3})^2\\\\\sf A=\pi\cdot4\cdot3\\\\\sf A=12\pi~cm^2\end{array}}$