A square is a very simple, common shape. It consists of 4 corners and 4 sides. All the angles are 90*. to find the area you use w x l. You multiply one side by the other (Not that it matters; all of them are the same length). You find the perimeter by multiplying the length of the sides by 4. Ex: 8 x 8 = 64 cm square = Area. 8 x 4 = 32 cm = Perimeter
Rectangle
rectangles are similar to squares. they are the same as squares except for two sides are different than the other two. The formula for area is the same: W x l. The formula for perimeter is l x 2 + w x 2. Ex:
Parallelogram
parallelograms follow a similar formulas. Area is w x h, and the perimeter is w x 2 + h x 2. ex 8 x 8 = 64 cm square = area. 8 x 2 + 8 x 2 = 32 cm square = perimeter.
Equilateral Triangle
an equilateral triangle is a triangle that has equal lengths of sides. The area is w x h \ 2. The perimeter is l x 3. ex: 3 x 3 \ 2 = 4.5 cm square = area. 3 x 3 = 9 cm = perimeter
Trapazooid
The area of a trapezoid is (b1 + b2 \ 2) x h. the perimeter is b1 + b2 + s1 + s2 ex: (2 + 4 \ 2) x 4 = 12 cm square = area 2 + 4 + 5 + 5 = 16 cm = perimeter
Circle
The circle is much different from the others. it has no corners and one side. the area is r (d \ 2) squared x Pi. Perimeter is d x pi. ex 2 x 2 + 3.14 = 12.56 cm square = area. 4 x 3.14 = 12.56 cm = perimeter