Skill: Find area of triangles

To find the area of a triangle, use:

$$A=\frac{1}{2}bh$$

• $b$ is the length of the chosen base.
• $h$ is the perpendicular height—the distance straight up or down from the base to the opposite vertex.
• The height is not always a slanted side.
• Area is written in square units.

Think of a triangle as half of a parallelogram or rectangle with the same base and height.

Example: Find the area of a triangle with a base of $8\text{ cm}$ and a perpendicular height of $5\text{ cm}$.

1. Identify the measurements:

$$b=8\text{ cm}, \qquad h=5\text{ cm}$$

2. Substitute them into the formula:

$$A=\frac{1}{2}(8)(5)$$

3. Multiply:

$$A=\frac{1}{2}(40)=20$$

4. Include square units:

$$\boxed{20\text{ cm}^2}$$

The area of the triangle is $\boxed{20\text{ square centimeters}}$.