Question 316556
Let w=width
Let l=length

The width is 3 metres less than the length:

w = l - 3

or, l = w+3


Perimeter of a rectangle is given by: P=2w+2l

Plug l=w+3 into the perimeter equation and solve for w:


P=2w+2l
P=2w + 2(w+3)
14 = 2w + 2w +6
8 = 4w
w = 2

The length is l = w+ 3 = 2+3 = 5.



Angle question:

Let a=first angle, b=2nd angle, c=3rd angle

b=2a
c=a+20


All triangles must have angle sums of 180 degrees, so:


a+b+c = 180


Now plug in b=2a and c=a+20 into this equation:


a+b+c=180
a + 2a + a+20 = 180
4a + 20 = 180
4a = 160
a = 40


The first angle is 40 degrees.