To find the area and perimeter of triangles, you can follow these easy steps:

Area Calculation

1. Find the Base and Height: Pick one side of the triangle to be the base (we’ll call it $b$). Then, measure how tall the triangle is from the base to the top point (this is called the height and we’ll use $h$ for this).

2. Use the Area Formula: You can find the area ($A$) of a triangle using this formula:

   $$A = \frac{1}{2} \times b \times h$$

   For example, if the base is 8 cm and the height is 5 cm, the area would be:

   $$A = \frac{1}{2} \times 8 \times 5 = 20 \text{ cm}^2$$

Perimeter Calculation

1. Measure All Sides: You need to know the lengths of all three sides of the triangle (we'll call them $a$, $b$, and $c$).

2. Use the Perimeter Formula: To find the perimeter ($P$), just add up the lengths of the sides like this:

   $$P = a + b + c$$

   For example, if one side is 5 cm, another side is 7 cm, and the last side is 9 cm, then:

   $$P = 5 + 7 + 9 = 21 \text{ cm}$$

Summary

• Area Formula: $A = \frac{1}{2} \times b \times h$
• Perimeter Formula: $P = a + b + c$