Lesson Notes By Weeks and Term v4 - JHS 1
Measurement
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Measurement
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Subject: Mathematics
Class: JHS 1
Term: 3rd Term
Week: 1
Grade code: B7.3.2.1.3
Strand code: 3
Sub-strand code: 2
Content standard code: B7.3.2.1
Indicator code: B7.3.2.1.3
Theme: GEOMETRY AND MEASUREMENT
Subtheme: Measurement
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This lesson introduces learners to the concept of the area of a triangle. Instead of just memorizing a formula, we will discover *why* the formula works by relating it to the area of a rectangle, a shape they are already familiar with. Understanding area is a crucial skill in many aspects of Ghanaian life, from farming and construction to design and art. This lesson builds on learners' prior knowledge of rectangles and empowers them with the ability to calculate the space inside one of the most common shapes in our environment.
Introduction: Connecting to What We Already Know
Teacher: "Good morning, class! Look at the shape of a slice of yam or the gable end of a house roof. What shape do you see? (A triangle). Excellent! Now, we know how to find the area of a square or a rectangle. We multiply the length by the width. Today, we are going to learn how to find the area of a triangle, and you will see that it is very closely related to the area of a rectangle." Part A: Deriving the Formula for the Area of a Triangle
The key to understanding the area of a triangle is to see its relationship with a rectangle.
Step 1: Start with a Rectangle Let's draw a rectangle. We know the area of a rectangle is `Length × Width`. For our purpose, let's call the length the base (b) and the width the height (h). So, Area of Rectangle = base × height