Finding the Area of a Triangle

• Mathematics
• Secondary Education

Learning Objective

At the end of the lesson, you will be able to calculate the area of a triangle using the base and height.

What do you already know about triangles?

Triangle Basics

A triangle is a polygon with three sides and three angles.

Types of Triangles

Triangles can be classified as equilateral, isosceles, or scalene based on their side lengths.

Base and Height

To find the area of a triangle, we need to know the length of the base and the height.

Area Formula

The formula to calculate the area of a triangle is: Area = 1/2 * base * height.

Example 1

Find the area of a triangle with a base of 6 cm and a height of 4 cm.

Example 2

Find the area of a triangle with a base of 9.5 m and a height of 3.2 m.

Practice Exercise

Calculate the area of the following triangles: (1) base = 5 cm, height = 8 cm; (2) base = 12.3 m, height = 6.5 m.

Write down 3 things you learned in this lesson.

Have students enter three things they learned in this lesson. With this they can indicate their own learning efficiency of this lesson.

Write down 2 things you want to know more about.

Here, students enter two things they would like to know more about. This not only increases involvement, but also gives them more ownership.

Ask 1 question about something you haven't quite understood yet.

The students indicate here (in question form) with which part of the material they still have difficulty. For the teacher, this not only provides insight into the extent to which the students understand/master the material, but also a good starting point for the next lesson.