Area of triangles
A triangle is exactly half of a rectangle or parallelogram! Once you know that, you can find its area easily using a simple formula. It's all about base, height, and dividing by two.
Concept
The area of a triangle is the amount of space inside it. The formula is closely related to the area of a parallelogram. **The Formula: A = ½ x b x h** * **A** stands for Area. * **b** stands for the **base** of the triangle. This is one of its sides. * **h** stands for the **height** of the triangle. The height is the perpendicular distance from the base to the opposite vertex (corner). It must form a right angle (90°) with the base. **Why does this work?** Imagine any triangle. If you make an exact copy of it, you can rotate the copy and fit it together with the original to form a parallelogram. The area of that parallelogram is **base x height**. Since the triangle is exactly half of that parallelogram, its area is **½ x base x height**. **Finding the Base and Height** * The **base** can be any side of the triangle. * The **height** is a line drawn from the opposite corner that is **perpendicular** to the base. This means it forms a 90° angle. * In a right triangle, the two legs are the base and height. * In other triangles, the height might be inside the triangle or sometimes even outside! **Example:** A triangle has a base of 10 cm and a height of 6 cm. 1. **Formula:** A = ½ x b x h 2. **Substitute:** A = ½ x 10 x 6 3. **Solve:** * You can multiply in any order. It's often easiest to multiply the numbers first: 10 x 6 = 60. * Then take half: ½ of 60 is 30. * Or, take half of an even number first: ½ of 10 is 5, then 5 x 6 = 30. 4. **Answer:** The area is 30 square centimeters (30 cm²). **Key Idea:** The most important part is identifying the correct base and height. The height must always be perpendicular to the base.
Try it
Practice: Area of triangles.