Circles, Sectors & Arcs: Quiz 4 - Answers
Part 1
1)
a) 9π cm2
b) 27π cm2
c) 75π cm2
d) 24π cm2
2) 8π cm2
3) 36π cm2
Part 2
1)
a) 42.8 cm2
b) 51.3 cm2
c) 105 cm2
d) 110 cm2
2) 30°
3) 240°
4) 72.4°
5) 31.1°
6) 7.9 cm
7) 3 cm
Part 1
Do not use a calculator for the following questions.
1) Work out the area of the following sectors. Give your answers in exact form (i.e. in terms of π).
2) We have a semi-circle with a radius of 4 cm. What is the area of the semi-circle in terms of π. Feel free to draw a sketch to help you understand what is happening.
3) We have a sector that is a quarter of a circle. The sector has a radius of 12 cm. What is the area of the sector? Give your answer in terms of π.
Part 2
You may use a calculator for the questions in this part.
1) Work out the area of the following sectors. Give your answers to 3 significant figures.
2) A sector has an area of 3π cm2 and a radius of 6. What is the angle of the sector?
3) A sector has a radius of 12 cm and an area of 96π cm2. What is angle of the sector.
4) A sector has an area of 34π cm2 and a radius of 13 cm. What is the angle of the sector? Give your answer to 3 significant figures.
5) A sector has an area of 7π cm2 and a radius of 9 cm. What is the angle of the sector? Give your answer to 3 significant figures.
6) A sector has an area of 43 cm2 and an angle of 78°. What is the length of the radius? Give your answer to 2 significant figures.
7) A sector has an area of 12.7 cm2 and an angle of 159°. What is the length of the radius? Give your answer to 2 significant figures.