QUESTION A)
We know that 2W+L=13cm
If we multiply this by 2 we get 26cm and are left with L
Therefore, to find L, we do 33-26;
L=7cm
Next we times 7(L)by 3(amount of L) to give us 21
Now we take 21 from 33to give us 12.
4W=12
so we divide 12 by 4 to give us 3
W=3cm
Now, to work out the perimeter of a small rectangle, we do;
7+3=10
10x2= 20cm
ANSWER : 20cm
QUESTION B)
We know 5LW=60cm2
So LW=12cm2
We also know 3W=L
So, through trial and improvement we can tell;
L=6cm
W=2cm
We can check this using algebra.
Then, in order to find the perimeter of a small rectangle, we do,
6+2=8
8x2=16cm
ANSWER : 16cm
QUESTION C)
6LW=600mm
LW=100
Ax4A=100
A2=25
A=5mm
Therefore
B=20mm
Then, to work out the perimeter, we do:
20+5=25
25x2=50mm
ANSWER ; 50mm
QUESTION D)
I worked out my answer through trial and improvement:
W=4cm
L=5cm
We can check these using algebra.
Now we calculate the perimeter;
4+5=9
9x2=18cm
ANSWER : 18cm
QUESTION E)
Firstly, we know all horizontal lines add up to 2b as there is b at the bottom and we know all other vertical lines add up to another b, totalling at 2b.
We also know all vertical lines (apart from those labelled c) add to 2a for the same reason.
Finally we know the 2 lines labelled c add up to 2c.
So the perimeter must be 2a+2b+2c
ANSWER : 2a+2b+2c