Question

Numa pirâmide reta de altura 15 cm, a base é um triângulo equilátero de lado 4 cm. Quanto vale o volume da pirâmide, em cm³? (Apresentar resolução)

Answer 1

$\large\boxed{\begin{array}{l}\underline{\rm C\acute alculo~da~\acute area~da~base~B:}\\\sf B=\dfrac{\ell^2\sqrt{3}}{4}\\\\\sf B=\dfrac{\diagup\!\!\!\!\!\!4^2\sqrt{3}}{\diagup\!\!\!4}\\\sf B=4\sqrt{3}~cm^2 \\\underline{\rm Volume~da~pir\hat amide:}\\\sf V=\dfrac{1}{3}\cdot B\cdot H\\\\\sf V=\dfrac{1}{\diagdown\!\!\!\!3}\cdot4\sqrt{3}\cdot\diagdown\!\!\!\!\!\!15^5\\\sf V=4\sqrt{3}\cdot5\\\sf V=20\sqrt{3}~cm^3\end{array}}$