Square footage of a square or rectangle:
Multiply the length by the width to determine the square footage, or area, of a square or rectangle. length x width = area

Square footage of a triangle:
– Consider the longest side of the triangle the base.
– Measure a perpendicular line from the opposite angle to the base to determine the triangle’s height.
– Multiply the base by the height, and divide that number in half to determine the area. (base x height) /2 = area

Square footage of a circle:
– Find the center point of the circle.
– Measure from that point to the edge of the circle to determine the radius.
– Multiply the radius by itself.
– Then multiply that number by PI (3.14) to find the area of your circle. Square footage of an irregular shape:
– Break up the space into regular shapes (e.g., squares, rectangles, triangles, and circles.)
– Determine the area of each shape.
– Add the areas of each shape to come up with an approximate area of the bed. area of A + area of B + area of C = total area (approx.)

Cubic footage:
– If the thickness or depth of your material is measured in inches, convert it to feet.
– Determine the square footage of the space
– Multiply the square footage by the desired depth of the material to determine the cubic footage, or volume.

length x width x depth = volume

Perimeters:
It is important to know the perimeter of an area so that you will know how much edging material to buy.  The perimeter of standard shapes is simply the sum of the sides.

The perimeter of a circle (the circumference) is PI (3.14)  times its diameter.