Question

Find the surface area of the figure below.

A. 1949.77
B. 1947.79
C. 620
D. 523.14

Answer 1

What shape are the top and bottom?

Answer 2

circles !

Answer 3

Yay! (I knew you knew... just wanted to walk you through the thinking here...)

So, what is the formula for the area of a circle?

Answer 4

that's what i got stuck on here .

Answer 5

If you're doing these sorts of shapes, you have to have learned how to find areas of basic shapes like rectangles, triangles, circles, etc.

Do you have textbooks or online notes you can refer back to when you can't remember a formula? I can tell it to you this time, and it's ok if you can't always remember, but you need to have a place to look these up if you're not sure.

Answer 6

Area of circle = pi * radius * radius, or usually it's written as:\[\pi * radius ^{2}\]
or
\[\pi * r^{2}\]

Answer 7

Ok, so you have two circles, one on top and one on bottom... same size, so you'll find the area with π * r^2 and then you need to multiply by two since there are two circles.

Step 2:
Find the area of the outside.
Ask yourself... what shape is that? Imagine it is a can of soup or something... if you unwrap the label from a can, you have a rectangle shape. Does that make sense?

Answer 8

for the first step i got : 314.159265359

Answer 9

and ya that does make sense !