AI generatedGeometry and measuresKS3 / GCSE

Perimeter of a semicircle or quadrant

Perimeter of a semicircle or quadrant.

  • A sector uses the fraction of the whole circle.
  • Arc length comes from circumference; sector area comes from circle area.
  • Perimeter includes straight edges too. An annulus is outer-circle area minus inner-circle area.

Example 1

Find the perimeter of the semicircle. Give an exact answer.

Circle geometry, not to scaleNot to scale
Choose the formula for this shape.Substitute the labelled dimensions. Keep π exact when it appears.

Example 2

Find the perimeter of the quadrant. Give an exact answer.

Circle geometry, not to scaleNot to scale
Choose the formula for this shape.Substitute the labelled dimensions. Keep π exact when it appears.

Your turn

Question 1

Find the perimeter of the semicircle. Give an exact answer.

Circle geometry, not to scaleNot to scale
Check answer
Choose the formula for this shape.Substitute the labelled dimensions. Keep π exact when it appears.
Question 2

Find the perimeter of the quadrant. Give an exact answer.

Circle geometry, not to scaleNot to scale
Check answer
Choose the formula for this shape.Substitute the labelled dimensions. Keep π exact when it appears.
Question 3

Find the perimeter of the semicircle. Give an exact answer.

Circle geometry, not to scaleNot to scale
Check answer
Choose the formula for this shape.Substitute the labelled dimensions. Keep π exact when it appears.
Question 4

Find the perimeter of the quadrant. Give an exact answer.

Circle geometry, not to scaleNot to scale
Check answer
Choose the formula for this shape.Substitute the labelled dimensions. Keep π exact when it appears.
Question 5

Find the perimeter of the semicircle. Give an exact answer.

Circle geometry, not to scaleNot to scale
Check answer
Choose the formula for this shape.Substitute the labelled dimensions. Keep π exact when it appears.