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

The video tutorial explains how to calculate the length of an arc in a circle sector. It begins by identifying the given data, including the radius and angle of the sector. The tutorial then demonstrates how to calculate the circumference of the entire circle using the formula πD. Next, it shows how to find the arc length by using the given angle and proportion of the circle's circumference. The result is rounded to three significant figures, and the tutorial concludes with an explanation of the marks awarded for the problem.

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

• 6 centimeters

• 4 centimeters

• 5 centimeters

• 3 centimeters

Which formula is used to calculate the circumference of a circle?

• π * R

• 2 * π * R

• π * D

• 2 * π * D

If the radius of a circle is 4 cm, what is its diameter?

• 2 cm

• 4 cm

• 8 cm

• 6 cm

What is the reflex angle AOC in the problem?

• 100 degrees

• 360 degrees

• 160 degrees

• 260 degrees

To how many significant figures should the final answer be rounded?

• Four

• Three

• Two

• Five