a Rectangle is a quadrilateral that has two sets of congruent sides.
(area of a rectangle, = base*height)
The fence (70m) consists of only 3 sides, two of which are congruent. Two factors of 600 equal the sum of the dimensions of the fence. Confused?
20 & 30 are factors of 600(area)
20+20+30=70(perimeter of fence only)
The garden, unlike the fence, includes the wall, which is equal to 30(the side that's missing it's congruent piece)
100=20+20+30+30, these are the dimensions of the garden.
