Question

the figure below is a net for a triangular prism. what is the surface area of the triangular prism, in square meters?

Explanation:

Step1: Calculate area of rectangular faces

There are 3 rectangular faces. Two have dimensions 15 m by 13 m and one has dimensions 15 m by 9 m.
$A_{rect1}=15\times13 = 195$ (for each of the two 15 - 13 rectangles), $A_{rect2}=15\times9=135$
Total rectangular area $A_{r}=2\times195 + 135=390 + 135 = 525$

Step2: Calculate area of triangular faces

The triangles have base 15 m and height 9 m.
Area of a triangle formula is $A=\frac{1}{2}bh$.
$A_{t}=\frac{1}{2}\times15\times9=\frac{135}{2}=67.5$
Total triangular area $A_{tr}=2\times67.5 = 135$

Step3: Calculate total surface area

Add rectangular and triangular areas.
$A = A_{r}+A_{tr}=525 + 135=660$

Answer:

660