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Exercises: Arc Length and Area of a Sector

Practice★☆☆
A circle has radius $6$ cm. A sector has a central angle of $60^\circ$. Find the length of the arc, in terms of $\pi$.

A circle has radius $6$ cm. A sector has a central angle of $60^\circ$.

Find the length of the arc, in terms of $\pi$.

Solve
Practice★☆☆
A circle has radius $10$ cm. A sector has a central angle of $72^\circ$. Find the area of the sector, in terms of $\pi$.

A circle has radius $10$ cm. A sector has a central angle of $72^\circ$.

Find the area of the sector, in terms of $\pi$.

Solve
Practice★☆☆
A sector of a circle of radius $5$ cm has an arc length of $7$ cm. Find the central angle of the sector, correct to the nearest degree.

A sector of a circle of radius $5$ cm has an arc length of $7$ cm.

Find the central angle of the sector, correct to the nearest degree.

Solve
Practice★★☆
A circular pizza in a restaurant in Galway has a radius of $15$ cm. It is cut into $8$ equal slices. a) Find the central angle of each slice. b) Find the area of one…

A circular pizza in a restaurant in Galway has a radius of $15$ cm. It is cut into $8$ equal slices.

  1. a) Find the central angle of each slice.
  1. b) Find the area of one slice, correct to one decimal place.
  1. c) Find the perimeter of one slice, correct to one decimal place.
Solve
Practice★★☆
A windscreen wiper has a blade of length $40$ cm attached to a pivot. The wiper sweeps through an angle of $110^\circ$. The blade extends from $10$ cm to $50$ cm from…

A windscreen wiper has a blade of length $40$ cm attached to a pivot. The wiper sweeps through an angle of $110^\circ$. The blade extends from $10$ cm to $50$ cm from the pivot.

  1. a) Find the area of the region swept by the blade, correct to the nearest cm$^2$.
  1. b) Find the distance travelled by the tip of the blade (the point $50$ cm from the pivot) in one sweep, correct to the nearest cm.
Solve
Practice★★☆
A sector of a circle has a radius of $12$ cm and an area of $48\pi$ cm$^2$. a) Find the central angle of the sector. b) Find the length of the arc, in terms of $\pi$. c)…

A sector of a circle has a radius of $12$ cm and an area of $48\pi$ cm$^2$.

  1. a) Find the central angle of the sector.
  1. b) Find the length of the arc, in terms of $\pi$.
  1. c) Find the perimeter of the sector, correct to one decimal place.
Solve
Practice★★★
A sector of a circle has a perimeter of $30$ cm and a radius of $8$ cm. a) Find the arc length. b) Find the central angle, correct to the nearest degree. c) Find the…

A sector of a circle has a perimeter of $30$ cm and a radius of $8$ cm.

  1. a) Find the arc length.
  1. b) Find the central angle, correct to the nearest degree.
  1. c) Find the area of the sector, correct to one decimal place.
Solve
Practice★★★
A circle with centre $O$ has radius $10$ cm. Points $A$ and $B$ lie on the circle and $\angle AOB = 80^\circ$. a) Find the area of the sector $AOB$, correct to one…

A circle with centre $O$ has radius $10$ cm. Points $A$ and $B$ lie on the circle and $\angle AOB = 80^\circ$.

  1. a) Find the area of the sector $AOB$, correct to one decimal place.
  1. b) Find the area of triangle $AOB$, correct to one decimal place.
  1. c) Hence find the area of the segment between the chord $AB$ and the arc $AB$.
Solve
Practice★★★
A sector of radius $r$ cm has central angle $\theta^\circ$. The arc length is equal to the radius. a) Show that $\theta = \dfrac{180}{\pi}$. b) Hence show that the area…

A sector of radius $r$ cm has central angle $\theta^\circ$. The arc length is equal to the radius.

  1. a) Show that $\theta = \dfrac{180}{\pi}$.
  1. b) Hence show that the area of the sector is $\dfrac{r^2}{2}$.
  1. c) Find $r$ if the area of the sector is $50$ cm$^2$.
Solve