Question

l:b::7:5 and area is 1260cm²
find the perimeter of the rectangle

Answer 1

@megangray32
@JayDS
@BasedGod1122

Answer 2

l:b :: 7:5 means that l = 7x and b = 5x for some unknown

Answer 3

if you plug that into a rectangle, use the formula for area and set that equal to 1260, you should have your answer.

Answer 4

35X = 1260CM²

Answer 5

35x^2 watch for the squared. :)

Answer 6

WHAT?

Answer 7

(7x)(5x) = 35x^2

Answer 8

do you see that? :)

Answer 9

okay now waht

Answer 10

first get rid of that pesky 35 by division

Answer 11

how?

Answer 12

you have 35x^2 = 1260 right? So divide both sides by 35.

Answer 13

6?

Answer 14

almost, not quite since 35 * 6 = 210 :)

Answer 15

36?

Answer 16

good! :)

Answer 17

so now, x^2 = 36 any ideas?

Answer 18

so is x 6?

Answer 19

yahoo! you got it!

Answer 20

but we aren't done yet... :)

Answer 21

so l is 42 and b is 30?

Answer 22

good, so the perimeter is?

Answer 23

144?

Answer 24

yep yep!

Answer 25

nicely done

Answer 26

what is the units for perimeter 144 cm feet or what

Answer 27

well, the area is cm^2, so we have to be something in cm, and length is measured in cm.

Answer 28

so 144 cm like you said.