PERIMETER What Is a Polygon? polygon – a plane figure with three or more sides that are all straight. regular polygon – a polygon which sides and angles are ALL equal. Calculating the PERIMETER of regular polygons: The perimeter of a polygon is the SUM of all its length. • To find the perimeter of a polygon, ADD the length of all the sides together. Example: To find the perimeter of this square, we need to add the length of all its sides: 3 cm + 3 cm + 3 cm + 3 cm = 12 cm The perimeter of this square is 12 cm. © Copyright NewPath Learning. All Rights Reserved. Permission is granted for the purchaser to print copies for non-commercial educational purposes only. Visit us at www.NewPathLearning.com.
Another example: To find the perimeter of this triangle, we need to add the length of all its sides: 5 cm + 5 cm + 5 cm = 15 cm The perimeter of this triangle is 15 cm. © Copyright NewPath Learning. All Rights Reserved. Permission is granted for the purchaser to print copies for non-commercial educational purposes only. Visit us at www.NewPathLearning.com.
Calculating the PERIMETER of irregular polygons: irregular polygons – a polygon that does NOT have all equal sides and angles. To find the perimeter of this scalene triangle (a triangle with three sides of different lengths), we need to add the length of all its sides: 2 cm + 3 cm + 4 cm = 9 cm The perimeter of this scalene triangle is 9 cm. © Copyright NewPath Learning. All Rights Reserved. Permission is granted for the purchaser to print copies for non-commercial educational purposes only. Visit us at www.NewPathLearning.com.