I show a simple way to get the conversion factor between any two area units. For example, to find how many square inches is 1 square foot, first sketch a square foot (= a square with 1-foot sides). Then think how long the sides are in INCHES — in this case, they are 12 inches. Then it is simple to find the area of the square by multiplying 12 in × 12 in = 144 sq. in.
We use this simple idea to find, for example, the area of a square with 6-ft sides in square inches, or how many square yards are in a square miles. Not forgetting the metric units, I also show how to convert between square centimeters and square millimeters.
This way you won't be dependent on having the conversion factors on hand - as long as you can remember the factor between the corresponding units of length.
Area of parallelograms and triangles — video lesson
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