Triangles
Triangles have something in common with parallelograms. A triangle is one-half of a parallelogram, a rectangle, or a square. When we draw a diagonal through any parallelagram, we get two triangles that are mirror images of each other.
To find the area of a triangle, multiply the base by the height. Then divide by 2.
For example, here are the steps to find the area of triangle MNO, which is pictured here:
Step 1: Multiply the base by the height.
10×7=70
Step 2: Divide by 2.
70÷2=35
Answer: The area of MNO is 35 square centimeters.
Can you see why this works? Multiplying the base by the height is how we find the area of parallelograms, rectangles, and squares. We then divide by 2 because a triangle is one-half of one half of a parallelogram.
