Area of a Triangle A ½bh. Area 12 bh. Area of a Rectangle A lb.
Triangle a b c.
P 2 6 3. Triangle a b c. Where a Length of the sides of a Square. Estimation and direct measurement of perimeter EMG5S To measure the perimeter of a rectangle a square or a triangle we simply measure the length of each side using a ruler and add up the sides to get the perimeter.