Area and Sector Calculations

The video tutorial explains how to calculate the area of a circle using the formula pi times the radius squared. It covers examples of semicircles, quarter circles, and sectors, demonstrating how to adjust the formula for each shape. The tutorial includes practice problems to reinforce the concepts, with solutions provided for calculating areas in both fractional and decimal forms.

What is the formula for calculating the area of a circle?

• pi times the radius

• pi times the diameter squared

• pi times the radius squared

• 2 times pi times the radius

If the diameter of a semicircle is 12 cm, what is the radius?

• 6 cm

• 12 cm

• 3 cm

• 24 cm

How do you calculate the area of a semicircle?

• pi times the radius squared

• Half of pi times the radius squared

• Half of pi times the diameter squared

• pi times the diameter squared

What is the area of a semicircle with a radius of 6 cm?

• 12 pi cm²

• 18 pi cm²

• 24 pi cm²

• 36 pi cm²

What is the area of a quarter circle with a radius of 9 cm?

• 81 pi cm²

• 20.25 pi cm²

• 18 pi cm²

• 63.6 cm²

How do you calculate the area of a quarter circle?

• pi times the radius squared

• Quarter of pi times the radius squared

• Half of pi times the radius squared

• pi times the diameter squared

What fraction of a circle is a sector with a 100-degree angle?

• 1/4

• 1/3

• 100/180

• 100/360

How do you calculate the area of a sector?

• Fraction of pi times the diameter

• Fraction of pi times the radius

• Fraction of pi times the diameter squared

• Fraction of pi times the radius squared

What is the area of a sector with a 70-degree angle and a radius of 10 cm?

• 175/9 pi cm²

• 70/360 pi cm²

• 81/4 pi cm²

• 63.6 cm²

What is the area of a sector with a 150-degree angle and a radius of 8 meters?

• 64.1 m²

• 150/360 pi m²

• 110.8 m²

• 81/8 pi m²