Question

I need help. I have no idea on this question

Answer 1

The total surface area is 450 mm^2

Explanation:

We have a pyramid with a triangular base, which the formula to calculate the total surface area is the following

`\begin{gathered} A_T=A_B+A_L \\ A_B=(b\cdot h)/(2) \\ A_L=3\cdot(b\cdot l)/(2) \end{gathered}`

Replacing:

`\begin{gathered} A_T=(20\cdot15)/(2)+3\cdot(20\cdot10)/(2) \\ A_T=150+300 \\ A_T=450 \end{gathered}`