GCSE Secondary Maths Age 13-17 - Geometry & Measures: Sector of a Circle - Explained

The video tutorial explains how to solve a geometry problem involving a sector of a circle and an equilateral triangle. It guides through calculating the area of the sector, the area of the triangle, and finding the shaded area by subtraction. The tutorial also covers converting the shaded area into a percentage of the sector's area, providing a step-by-step approach and emphasizing the importance of remembering key formulas for exams.

What is the radius of the circle sector described in the problem?

• 21 cm

• 7 cm

• 11 cm

• 14 cm

What is the formula used to calculate the area of a sector?

• Theta/360 * π * R^2

• Base * Height / 2

• π * R^2

• 1/2 * AB * sin C

What is the angle at the center of the circle sector?

• 30 degrees

• 45 degrees

• 90 degrees

• 60 degrees

Which formula is used to find the area of the equilateral triangle?

• Base * Height / 2

• 1/2 * AB * sin C

• π * R^2

• Theta/360 * π * R^2

What is the side length of the equilateral triangle in the problem?

• 8 cm

• 7 cm

• 6 cm

• 5 cm

How is the area of the shaded region calculated?

• By multiplying the area of the triangle by the area of the sector

• By dividing the area of the triangle by the area of the sector

• By subtracting the area of the triangle from the area of the sector

• By adding the area of the triangle to the area of the sector

What is the final percentage of the shaded area relative to the whole sector?

• 60.5%

• 50.5%

• 70.5%

• 66.5%