40184

a)
2 * the second picture = 26
Subtract this from the first picture -
33-26 = 7
Therefore the length of a block = 7
21 + (4*length) = 33
Therefore (4 * length) = 12
Length = 3
Perimeter = 7 + 7 + 3 + 3 = 20cm

b)
If we call the length = b and the width = a - then, 3a = b
Then the area of the rectangle is 5a x 3a = 15a^2 = 60
Then a^2 = 4
a = 2
b = 6
Perimeter = 16cm

c)
If we call the length = b and the width = a - then, 4a = b
Then the area of the rectangle is 6a x 4a = 24a^2 = 600
Then a^2 = 25
a = 5
b = 20
Perimeter = 50mm

d)
5y=4x
4x(x+y) = 180
x(x+y) = 45
x^2 + xy = 45
5x^2 + x(5y) = 225
5x^2 + 4x^2 = 225
9x^2 = 225
x^2 = 25
x = 5
y = 4
Perimeter = 18cm