Question

Find the surface area of the triangular prism (above) using its net (below).

Answer 1

Answer:

It is 136

Step-by-step explanation:

Answer 2

Answer:

96 square units

Step-by-step explanation:

I think your question is missed of key information, allow me to add in and hope it will fit the original one.  Please have a look at the attached photo.

My answer:

• The length of the large rectangle is: 5
• The width of the large rectangle is: 7

=> Area of the large rectangle = length × width  = 7*5 = 35 square units

• The length of the middle rectangle is: 7
• The width of the middle rectangle is: 4

=> Area of the middle rectangle = length × width  = 7*4 = 28 square units

• The length of the small rectangle is: 7
• The width of the small rectangle is: 3            

=> Area of the small rectangle = length × width  = 7*3 = 21 square units

Area of top and the bottom triangles =2* $\frac{1}{2}bh$  $= 4*3 =12$  

Total surface area = 35 + 28 + 21 + 12 = 96 square units