# Lesson Notes By Weeks and Term - Senior Secondary 1

Polygons

TERM – 2ND TERM

WEEK THREE

Class: Senior Secondary School 1

Age: 15 years

Duration: 40 minutes of 5 periods each

Date:

Subject: Technical Drawing

Topic: POLYGONS

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

I.) Define a polygon

II.) Identify and draw out the types of a polygon

III.) Construct a regular hexagon given the length of the sides

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures,

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

 PRESENTATION TEACHER’S ACTIVITY STUDENT’S ACTIVITY STEP 1 INTRODUCTION The teacher explains the meaning of polygon and identify common types of polygons Students listens attentively to the teacher STEP 2 EXPLANATION Teacher constructs a regular hexagon given the length of the sides and also guide students to do the same. Students exhibit attentiveness and active engagement STEP 3 NOTE TAKING The teacher writes a summarized note on the board The students copy the note in their books

NOTE

POLYGONS

A polygon is a two-dimensional geometric shape with straight sides. It's formed by connecting points in space. The sides do not intersect, and the angles between adjacent sides sum up to 180 degrees. Polygons can have various numbers of sides, ranging from three to infinity.

Types of polygons

The following are some common types of polygons:

1. Triangle: A polygon with three sides. Triangles can be further classified based on the length of their sides and the size of their angles, such as equilateral, isosceles, scalene, acute, obtuse, or right triangle.

2. Quadrilateral: A polygon with four sides. Examples include squares, rectangles, parallelograms, rhombuses, trapezoids, and kites. Quadrilaterals can be classified based on their properties, such as the lengths of their sides and the sizes of their angles.

3. Pentagon: A polygon with five sides. One example is a regular pentagon, where all sides and angles are equal.

4. Hexagon: A polygon with six sides. Similar to the pentagon, a regular hexagon has all sides and angles equal.

5. Heptagon (or septagon): A polygon with seven sides.

6. Octagon: A polygon with eight sides.

7. Nonagon (or enneagon): A polygon with nine sides.

8. Decagon: A polygon with ten sides.

How to construct a regular hexagon given the length of the sides

Constructing a regular hexagon using a compass is quite straightforward.

1. Start by drawing a circle with the given radius (which is also the length of the hexagon's sides).
2. Without changing the compass width, place the compass on the circle's edge and make a mark on the circle.
3. Move the compass to the mark you just made and make another mark on the circle. Repeat this process until you've made six equally spaced marks around the circle.
4. Connect these marks with straight lines. You'll have a regular hexagon inscribed within the circle.

EVALUATION: 1.  Using the procedure above, construct a regular heptagon of length 5 cm

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively