Area and Volume Calculations

Mrs. Lopez guides Grade 7 students through the final lesson of Module 3, focusing on composite area problems. The lesson includes examples and exercises on calculating areas of complex shapes, such as circles, rectangles, semicircles, and triangles. Students learn to use strategies like subtracting areas of smaller shapes from larger ones and applying formulas for circles and rectangles. The lesson emphasizes the use of calculators for precise calculations.

What is the main focus of the lesson introduced by Mrs. Lopez?

• Exploring the perimeter of polygons

• Learning about the properties of triangles

• Understanding the area and circumference of circles

• Calculating the volume of cylinders

In Example 1, what is the strategy used to find the composite area of the shaded region?

• Multiplying the radii of the circles

• Dividing the area of the larger circle by the smaller circle

• Subtracting the area of the smaller circle from the larger circle

• Adding the areas of two circles

What value is used for pi in the calculations of Example 1?

• 3.14159

• 3.14 and fourteen hundredths

• 3.14

• 3.1416

In Exercise 1, how is the area of the grassy section determined?

• By dividing the area of the larger rectangle by the smaller one

• By multiplying the lengths of the rectangles

• By subtracting the area of a smaller rectangle from a larger rectangle

• By adding the areas of two rectangles

What is the length of the larger rectangle in Exercise 1?

• 4 units

• 2 units

• 5 units

• 3 units

In Example 2, what shapes make up the figure whose area is being calculated?

• A circle and a triangle

• A rectangle and a triangle

• A rectangle and a semicircle

• Two rectangles

What is the radius of the semicircle in Example 2?

• 2 meters

• 1 meter

• 3 meters

• 4 meters

In Example 3, what is the size of the square used in the problem?

• 20 by 20

• 15 by 15

• 25 by 25

• 10 by 10

How many triangles are subtracted from the square in Example 3?

• Five

• Two

• Three

• Four

What is the final area of the shaded region in Example 3?

• 150 cm²

• 116 cm²

• 200 cm²

• 100 cm²