Can someone please help me with my maths homework

A rectangle is twice as long as it is wide. If the perimeter 9cm find it's dimensions.

I have no idea how to answer it.

Please show your working out as well as the answer.

Thankyou so so much in advance! xx

That's easy,
Let x be the width

Width=x
Length=2x
Perimeter=x+2x+x+2x
=6x
9cm=6x
X=9/6
X=1.5cm

Width=1.5cm
Length=1.5cm x 2
= 3cm




Check~
1.5+1.5+3+3=9cm
:)

with this, you have 2 equations. make l= length and w=width.
equation 1- 2l + 2w = 9
equation 2- l = 2w

substitute. 2(2w) + 2w=9
4w + 2w = 9
6w = 9
w= 9/6 or 3/2

l= 2(3/2) = 3.

plug it in to the first equation! it should be right. :)

come on. rectangle so u put the shorter side as x and the longer side as 2x cause it says twice as long. add all sides together to find perimemter so 2x+2x+x+x=9 which is 6x=9 and x=3/2 so one side is 3/2cm and the other is 3cm

Perimeter = 9cm

2x = 1 side
x = the other side

9/2 = 4.5

4.5 = 2x + x
4.5 = 3x
x = 1.5 cm

one side: 1.5 cm
other side : 3 cm

Let l be length and w be width. We relate w and l as l=2w.
Perimeter P = 2l + 2w = 3l = 9 cm. therefore l = 3cm. Width is 1.5 cm.

The longest sides (2 sides) are 3cm each. The shortest sides (2 sides) are 1.5cm each.

2L+2W = 9
L = 2W
4W+2W = 9
6W = 9
W = 1.5
L = 3
Length = 3 cm
Width = 1.5 cm

L=2w

2l+2w=9

6w=9

w=3/2

L=3

proof

3+3+3/2+3/2=9