Calculating Area and Perimeter of Polygons

In this lesson, students learn to determine the area and perimeter of polygons on the coordinate plane. The teacher guides through calculating the perimeter by summing line segment lengths and finding the area using rectangles and triangles. Two methods for area calculation are compared, and students are encouraged to practice with provided examples.

What is the primary objective of lesson 9?

• To understand the concept of symmetry in polygons

• To learn about the history of polygons

• To determine the area and perimeter of polygons on the coordinate plane

• To explore different types of polygons

Why does Josette need to calculate the perimeter and area of her garden?

• To decide the shape of the garden

• To know how much fencing and dirt to purchase

• To calculate the cost of garden maintenance

• To determine the number of plants she can grow

How is the perimeter of a polygon calculated?

• By dividing the total length by the number of sides

• By subtracting the lengths of all sides

• By adding the lengths of all sides

• By multiplying the lengths of all sides

What is the perimeter of the polygon in the example?

• 30 units

• 40 units

• 50 units

• 60 units

How is the area of an irregular polygon calculated using rectangles?

• By estimating the area visually

• By using the formula for a circle

• By dividing the polygon into rectangles and summing their areas

• By dividing the polygon into triangles

What is the total area of the irregular polygon in the example?

• 52 square units

• 100 square units

• 76 square units

• 36 square units

What is one method to calculate the area of a polygon using triangles?

• By estimating the area visually

• By using the formula for a circle

• By calculating the base times height and dividing by two

• By using the Pythagorean theorem

What is the area of the hexagon calculated using triangles?

• 48 square units

• 60 square units

• 36 square units

• 24 square units

What is the second method for calculating the area of a polygon?

• Using only triangles

• Using two triangles and a rectangle

• Using only rectangles

• Using circles

What should students do after watching the video?

• Take a break and not think about the lesson

• Forget about the lesson

• Try to apply the concepts in practice problems

• Watch another unrelated video