## alainabbyboo22 3 years ago Find the surface area of the figure below. A. 200 in2 B. 88 in2 C. 42.5 in2 D. 85 in2

1. alainabbyboo22

2. alainabbyboo22

am i doing the same thing as on the circle one ?

3. JakeV8

Pretty much... no circles here though ;) You're the teacher here... what should we do first? (jk, I'll help)

4. alainabbyboo22

lol i'd hope so ! cause otherwise i'll never be able to be the teacher . xD

5. alainabbyboo22

pi * 9^2 ?

6. JakeV8

Why pi? I don't see any circles in that diagram. What shapes are there?

7. alainabbyboo22

oh .. well .. 9*4*4 ?

8. JakeV8

I don't understand yet ;) It looks like you multiplied 9 * 4. Is that the area of a side of the shape?

9. alainabbyboo22

i really don't understand this one . i have no idea what i have to do . ):

10. JakeV8

What shape do you see on the sides of that pyramid?

11. alainabbyboo22

triangles .

12. JakeV8

Area of a triangle: = 1/2 * base * height You had the right idea of multiplying by four, though... there are four sides.

13. JakeV8

So, for the four triangle sides, your area of each side will be 1/2 * 4 * 9 1/2 * 4 * 9 = 18 And there are 4 of those triangle sides, so 4 * 18 = 72 But you still need to add the area of the square base.

14. alainabbyboo22

where do i go from there then ?

15. JakeV8

what is the area of the bottom? The shape of the bottom is a square with sides 4...