Question

The perimeter of a rectangle is 20 cm and its dimensions are tripled. What is the perimeter of the larger rectangle?

Answer 1

So
2(l+b) = 20
Right now if dimensions are tripled the Length = 3l, breadth = 3b
So
Perimeter = 2(3l+3b) = 2*3(l+b) [Find it now]
Understood this? :)

Answer 2

12+12+3+3=30

Answer 3

no i thought it was 10 y fault

Answer 4

20 cm

23 cm

40 cm

60 cm

Answer 5

Did you understand what I said? :)

Answer 6

60

Answer 7

But did you get the concept? @scarroll40

Answer 8

yes

Answer 9

An outside circular ring has a circumference of 200 cm. What is the circumference of an inner ring which is 25 cm shorter in radius? Both circles have the same center.

Answer 10

Okay. We know that circumference is 2(pi)r
Make an equation. 2(pi)r = 200
Calculate radius.

Answer 11

you would do 20*3 and you would get your answer which is 60

Answer 12

(pi)r = 100
r = 100/pi
What do I take as the value of pi?

Answer 13

r = 100/3.14
Rest you can solve.

Answer 14

i did that but dont match the multiple choice

Answer 15

43.0 cm

50.0 cm

74.4 cm

96.1 cm

Answer 16

?

Answer 17

the closestthing go to the anser was a but i am not sure if that is corrct or not

Answer 18

\[C = 2\pi ~r\]
\[\frac{C}{2\pi} = r\]
\[\frac{C}{2\pi}-25 = r-25\]
therefore:\[C'=2\pi(\frac C{2\pi}-25)\]
sounds about right to me

Answer 19

That looks like it, and there is an answer up there that goes along with it.

Answer 20

It might help to simplify that a bit: