Arc length

The Maths Habit

  1. Find the circumference of a circle with radius 5 cm, to 1 decimal place.

    31.4 cm

  2. Find the circumference of a circle with diameter 13 m, to 1 decimal place.

    40.8 m

  3. Find the circumference of a circle with radius 8.5 mm, to 1 decimal place.

    53.4 mm

Which has more crust: a quarter of a 30 cm pizza or a third of a 24 cm pizza?

A third of the 24 cm pizza: about 25.1 cm of crust against 23.6 cm.

What fraction of the circle is this?

14

The radius is 7 cm.
What is the diameter?

14 cm

Arc
Part of the circumference of a circle.

Arc length = fraction of the circle × circumference

Find the arc length to 1 decimal place.

Find the arc length to 1 decimal place.

Arc =
120360fraction of the circle
× π ×
18circumference
Answer18.8 cm
Arc =
45360fraction of the circle
× π ×
20circumference
Answer7.9 cm
Arc =
120360fraction of the circle
× π ×
18circumference
Answer18.8 cm
Arc =
150360fraction of the circle
× π ×
8circumference
Answer10.5 cm
Arc =
120360fraction of the circle
× π ×
18circumference
Answer18.8 cm
Arc =
80360fraction of the circle
× π ×
12circumference
Answer8.4 cm
Arc =
120360fraction of the circle
× π ×
18circumference
Answer18.8 cm
Arc =
240360fraction of the circle
× π ×
8circumference
Answer16.8 cm
Arc =
120360fraction of the circle
× π ×
18circumference
Answer18.8 cm
Arc =
40360fraction of the circle
× π ×
9circumference
Answer3.1 cm

Arc length worksheet, page 1

Arc length worksheet, page 2

Answer sheet

  1. An arc of a circle is 5π cm long. The radius of the circle is 10 cm. What is the angle at the centre?

    90°

  2. Find the perimeter of a sector with radius 6 cm and angle 60°, to 1 decimal place.

    18.3 cm

  1. Find the arc length to 1 decimal place.

    6.3 cm
    72°5 cm

  2. Find the arc length to 1 decimal place.

    30.5 cm
    250°7 cm

  3. Find the perimeter of the sector to 1 decimal place.

    22.5 cm
    100°6 cm
Exit tickets to print