Question

The bottom shape is a cube with base edges of 6 inches. The top shape is a right pyramid with a height of 4 inches. What is the surface area of this composite figure?

180 in2

60 in2

240 in2

36 in2

Answer 1

If you're not sure how to do this, simply break the composite figure into two pieces: one piece (the upper piece) is a square pyramid and the lower piece is a cube

Answer 2

Keep in mind that the bottom of the pyramid and the top of the cube will be ignored because those aren't on the outside of the composite figure

Answer 3

Tell me what you get when you finish

Answer 4

ok hold on

Answer 5

alright

Answer 6

i must of done something wrong because i got 260

Answer 7

what did you get for the cube part?

Answer 8

remember to ignore the top face of the cube

Answer 9

i got 216 with the top face.

Answer 10

and without?

Answer 11

180

Answer 12

good

Answer 13

now what about the pyramid

Answer 14

this time, we're ignoring the bottom face of the pyramid

Answer 15

ok ignoring the bottom face i got 80

Answer 16

how did you find the area of each triangular face?

Answer 17

oh. ok thats where i messed up.

Answer 18

we have something like this

Answer 19

so we need to find h (the slant height) to find the area of each triangular face

Answer 20

well the height is 5, correct?

Answer 21

good, so the area of each triangle is?

Answer 22

15

Answer 23

you got it, so the total lateral surface area is then what

Answer 24

15 x 4 = 60

Answer 25

good, now add that onto the surface area you got for the cube

Answer 26

ignoring the top face of the cube of course

Answer 27

240

Answer 28

you got it