Lesson Notes By Weeks and Term v4 - SHS 2
MEASUREMENT
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MEASUREMENT
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Subject: Mathematics
Class: SHS 2
Term: 2nd Term
Week: 9
Grade code: 2.3.2.LI.2
Strand code: 3
Sub-strand code: 2
Content standard code: 2.3.2.CS.2
Indicator code: 2.3.2.LI.2
Theme: GEOMETRY AROUND US
Subtheme: MEASUREMENT
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This lesson introduces the concepts of angles of elevation and depression, which are practical applications of trigonometry. In Ghana, we see these principles in action everywhere: from a surveyor in Accra determining the height of a new building, to a farmer in the Volta Region estimating the height of a palm tree, or a sailor off the coast of Takoradi navigating using a lighthouse. By understanding these concepts, we can measure heights and distances that are otherwise difficult or impossible to measure directly. This lesson will equip learners with the skills to model and solve such real-world problems.
Prerequisite Knowledge: Learners should have a firm understanding of basic trigonometric ratios (Sine, Cosine, Tangent) in a right-angled triangle. A quick recap: SOH: Sin(θ) = Opposite / Hypotenuse CAH: Cos(θ) = Adjacent / Hypotenuse TOA: Tan(θ) = Opposite / Adjacent Concept 1: Angle of Elevation
The angle of elevation is the angle formed between the horizontal line of sight and the upward line of sight to an object that is above the observer's eye level.
Key Idea: Think of an elevator – it goes UP. The angle of elevation is always measured *upwards* from a horizontal line. It is always *inside* the right-angled triangle.