Question

A circular piece of metal has a radius of 3.5 meters.
The metal sells for $3.25 per square meter.

What is the total cost of the circular piece of metal?



A.
$11.38


B.
$38.47


C.
$71.44


D.
$125.01

Answer 1

first find the area of the metal

Answer 2

Do you remember the formula for the area of a circle?

Answer 3

not really

Answer 4

wait yes 3.14

Answer 5

The formula is
\[\pi r ^{2}\]

Answer 6

where r is the radius

Answer 7

so 9.8596

Answer 8

nope

Answer 9

what's the radius of the circle?

Answer 10

umm 3.5

Answer 11

yep, so plug it into the formula and tell me what the area is

Answer 12

10.99

Answer 13

no

Answer 14

what is 3.5^2

Answer 15

12.25

Answer 16

correct. now multiply that by pi

Answer 17

38.465

Answer 18

yep, 38.5 works

Answer 19

ok, so that is the area of the metal

Answer 20

now we need to multiply that value by 3.25 to get the cost

Answer 21

okie so do we multiply 3.25 by π

Answer 22

no, multiply it by the area

Answer 23

which is -3- 3.5?

Answer 24

you just calculated the area

Answer 25

oh 38.5

Answer 26

38.5 x 3.25

Answer 27

125.125

Answer 28

so D?

Answer 29

yep

Answer 30

:D ty!

Answer 31

no problem