Question

Example: SA= surface area SA= 2ab + 2bc + 2ac( SA= 2Iw + 2wh + 2Ih) a. I=3 b. w=4 c. h=5 =2(3.4) 2(4.5) 2(3.5) =2(12) 2(20) 2(15) 24+40+30= 94 SA=94Here’s the two problems I really need help on: 1. a. r=12 b. r=16 c. d=102. a. r=6, h=12 b. r=2,h=10 c. r=3,h=5

Answer 1

We have that the surface area of a cube is given by:

`SA=6a^2`

Where a is the side of the cube.

Now, for 1, we will have:

a)

`SA_(a12)=6(12)^2\Rightarrow SA_(a12)=864`

b)

`SA_(r16)=6(16)^2\Rightarrow SA_(r16)=1536`

c)

`SA_(r10)=6(10)^2=600`

Now, the surface area for a cylinder we will have that is given by the expression:

`SA=2\pi rh+2\pi r^2`

Then for b, we will have:

a)

`SA=2\pi(6)(12)+2\pi(6)^2\Rightarrow SA=216\pi`

b)

`SA=2\pi(2)(10)+2\pi(2)^2\Rightarrow SA=48\pi`

c)

`SA=2\pi(3)(5)+2\pi(3)^2\Rightarrow SA=48\pi`