Question

What is the surface area of this triangular pyramid?

Answer 1

now, taking a peek at the picture above, let's notice, the pyramid is really just 4 triangles, three standing up and one lying down.

`\stackrel{ \textit{\LARGE Areas} }{\stackrel{ \textit{triangles standing up} }{3\left[\cfrac{1}{2}(\underset{b}{5})(\underset{h}{7}) \right]}~~ + ~~\stackrel{ \textit{triangle lying down} }{\cfrac{1}{2}(\underset{b}{5})(\underset{h}{4.3})}}\implies 52.5+10.75\implies \text{\LARGE 63.25}~yd^2`