Question

b

Answer 1

Can't view the photo. Post it as png

Answer 2

Sorry, try this

http://imageshack.us/content_round.php?page=done&l=img843/8582/truncatedpyramid.jpg&via=mupload&newlp=1

Answer 3

2 formulas we need are

area of a triangle = 1/2 b*h
area of a trapezoid = 1/2 (a+b)h

So we have 3 sides (trapezoids) plus a top and bottom (triangles)

top and bottom are 3/4/5 triangles and we know the height of the trapezoid is 12. Figure out the area of all 5 sides and add them together.

I believe that's it.

Answer 4

Oh ok...I guess I had the wrong formula then...I thought for some reason it was SA= (1.2) pl +b

Answer 5

This is the surface area of a pyramid formula. But the fact that they chopped off the top changes it.

If you knew the total height, you could calculate it as the difference of 2 pyramids (the larger one - the one chopped off)

Answer 6

confusing....

Answer 7

Surface area is just the sum of the areas of all the sides...so even if you forget the surface area formula for something, you can just calculate the area of each side and sum them. For example: area of a square is a*a. The surface area of a cube is 6a^2, because you have 6 sides which are all squares.

Answer 8

So in this example the top and bottom are triangles and the 3 sides are now trapezoids...we can use the formulas for area of a triangle and area of a trapezoid to figure out the areas of each side and then add them all together.

The only other information you need to know to make it work, it to know that the triangles are 3-4-5 triangles, so you can calculate the 3rd side.

Answer 9

A= 1/2bh
A= 1/2 (3) (4)
A =1/2 12
A = 6

Is this correct?

Answer 10

That's just for the top triangle....now you have to do it for the bottom triangle and the sides too....5 calculation, then sum them.

Answer 11

A= 1/2 bh
A= 1/2 (6)(8)
A= 1/2 48
A= 24



This is what I got for the bottom.

Answer 12

Top = 1/2 (3) (4) = 6
Bottom = 1/2 (6)(8) = 24
Side (1) = 1/2 (3+6) (12) = 54
Side (2) = 1/2 (4+8) (12) = 72
Side (3) = 1/2 (6+10) (12) = 96

Total = 252 sq cm. is what I get.

Answer 13

yes...you have the idea now...there may be a formula for this type of shape...but it's good to know how to deconstruct it. in case you ever get stuck and can't remember all the formulas.

Answer 14

Yeah it's kinda complicated.

Answer 15

Thank you for your help, I really appreciate it, I've been stuck on it forever trying to figure out if I'm doing it right or not.