Exploring the Angles and Sides of Polygons
Exploring the Angles and Sides of Polygons
Learning objective
Lesson duration is: 40 minItems in this lesson
Exploring the Angles and Sides of Polygons
Learning objective
Learning Objectives
At the end of the lesson, you will be able to calculate the sum of the interior angles of triangles and quadrilaterals and identify the number of sides they have.
What do you already know about the angles and sides of polygons?
What is a Polygon?
A polygon is a closed, two-dimensional shape with straight sides. Examples include triangles, quadrilaterals, and pentagons.
Understanding Triangles
Triangles have 3 sides and 3 angles. The sum of their interior angles is always 180 degrees.
Understanding Quadrilaterals
Quadrilaterals have 4 sides and 4 angles. The sum of their interior angles is always 360 degrees.
Calculating Interior Angles
To find the sum of interior angles of a polygon, use the formula: (n - 2) × 180, where n is the number of sides.
Interactive Activity
Work in pairs to identify and calculate the angles of given polygons using the formula.
Summary of Key Points
Polygons have straight sides. Triangles: 3 sides/180°, Quadrilaterals: 4 sides/360°. Use the formula (n - 2) × 180 for interior angles.
Assignment
Calculate the sum of the interior angles for a pentagon and a hexagon. Show your calculations.
Write down 3 things you learned in this lesson.
Write down 2 things you want to know more about.
Ask 1 question about something you haven't quite understood yet.
