Answer:

Step-by-step explanation:
The surface area of the triangular prism consists of three rectangles and two triangles.
Rectangle One - 5 x 12 = 60 cm^2
Rectangle Two - 4 x 12 = 48 cm^2
Rectangle Three - 3 x 12 = 36 cm^2
Triangles - 2 x 1/2 x 3 x 4 = 12 cm^2
Thus, the total surface area of the solid is 
Answer:
3) 27 cubed
4) 72 cubed
5) 125 cubed
8) 27 cubed. 3 is the length, 3 is the width, and 3 is the height.
9) 72 cubed. 6 is the length, 3 is the width, and 4 is the height.
10) 125 cubed. 5 is the length, 5 is the width, and 5 is the height.
Step-by-step explanation
Here's what to show if your teacher requires for you to show your work.
3) 3 x 3 x 3 = 27
4) 6 x 3 x 4 = 72
5) 5 x 5 x 5 = 125
8) 3 x 3 x 3 = 27
9) 6 x 3 x 4 = 72
10) 5 x 5 x 5 = 125
These are the ones I'd suggest putting the up and down form on.
10) and 5) Also put 5 x 5 = 25. 4) and 9) Also put 6 x 3 = 18.
<em>2 3</em>
25 18
<u>x 5 </u> <u>x 4 </u>
125 72
Hoped this answered everything! Feel free to ask me if there's something I missed! :)
In order to get an 81 average,
the student has to get 81x5=405
71+96+90+73+?=405
330+?=405
405-330=75
he needs to get an 75