Lesson Notes By Weeks and Term v4 - SHS 1
SPATIAL SENSE
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SPATIAL SENSE
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Subject: Mathematics
Class: SHS 1
Term: 2nd Term
Week: 1
Grade code: 1.3.1.LI.5
Strand code: 3
Sub-strand code: 1
Content standard code: 1.3.1.CS.1
Indicator code: 1.3.1.LI.5
Theme: GEOMETRY AROUND US
Subtheme: SPATIAL SENSE
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This lesson introduces learners to the fascinating world of polygons, which are the building blocks of many shapes we see every day. From the hexagonal shape of a honeycomb to the rectangular shape of our classroom doors and the pentagonal star on our national flag, understanding polygons is essential. We will explore the special family of four-sided polygons called quadrilaterals and then discover a powerful formula to find the sum of angles inside any polygon, no matter how many sides it has. This knowledge is crucial not just for passing examinations, but for practical fields like construction, design, art, and engineering right here in Ghana.
A. What are Polygons and Quadrilaterals? A Polygon is any 2D closed shape made up of straight line segments. Examples: Triangle (3 sides), Quadrilateral (4 sides), Pentagon (5 sides), Hexagon (6 sides). A Quadrilateral is a polygon with exactly four (4) sides and four (4) angles. The sum of the interior angles of any quadrilateral is always 360°.
Key Properties of Common Quadrilaterals:
| Quadrilateral | Properties of Sides | Properties of Angles | Properties of Diagonals | | :--- | :--- | :--- | :--- | | Square | - All 4 sides are equal. - Opposite sides are parallel. | - All 4 angles are 90°. | - Diagonals are equal. - Diagonals bisect each other at 90°. | | Rectangle | - Opposite sides are equal and parallel. | - All 4 angles are 90°. | - Diagonals are equal. - Diagonals bisect each other (not at 90°). | | Parallelogram | - Opposite sides are equal and parallel. | - Opposite angles are equal. - Consecutive angles add up to 180°. | - Diagonals bisect each other. | | Rhombus | - All 4 sides are equal. - Opposite sides are parallel. | - Opposite angles are equal. | - Diagonals bisect each other at 90°. - Diagonals are not equal. | | Trapezium | - One pair of opposite sides is parallel. | - No general angle properties. | - No general diagonal properties. | | Kite | - Two pairs of adjacent sides are equal. | - One pair of opposite angles is equal. | - One diagonal is the perpendicular bisector of the other. |
B. Sum of Interior Angles of a Polygon