Circles and sectors
mathswariz.uk/worksheets/gcse-circles-and-sectors/
Do Now
Grades 4–6The first question is what today's lesson needs. The others bring back earlier topics.
- A1Needed today[1 mark]
A rectangle has area cm and width cm. Find its length.
Answer - A2From chapter 4[1 mark]
Find the 10th term of the sequence .
Answer - A3From chapter 7[1 mark]
Describe the locus of points 4 cm from a point .
Answer - A4Last lesson[1 mark]
Make the subject of .
Answer
Example, then your turn
Grades 4–6Your teacher works through each example with you. Then try the one beside it.
A round mat has diameter m. Work out its area, to s.f.
- B1[2 marks]
A round mat has diameter m. Work out its area, to s.f.
Answer
Work out the area of the sector, to s.f.
- B2[2 marks]
Work out the area of the sector, to s.f.
Answer
Practice
Grades 5–7- C1[2 marks]
Work out the perimeter of the semicircle, to s.f.
Answer - C2[2 marks]
The two circles have the same centre. Work out the area of the shaded ring in terms of .
Answer
- C3[3 marks]
Work out the perimeter of the sector. Give it in the form .
Answer - C4[2 marks]
The arc of the sector is cm long. Work out the angle of the sector.
Not drawn accurately Answer - C5[3 marks]
A round pond has area m. Work out its diameter, to s.f.
Answer - C6[3 marks]
A wheel of diameter cm rolls m. How many complete turns does it make?
Answer
Exam-style questions
Grades 6–8- D1
A small pizza has a diameter of cm and costs £. A large pizza has a diameter of cm and costs £. Amir says, "The large pizza is twice as wide, so it has twice the area. It costs more than three times as much, so it is worse value."
(a)[2 marks]Show that the large pizza has times the area of the small pizza.
(b)[3 marks]Is Amir right that the large pizza is worse value? You must show your working.
Total for D1: 5 marks
- D2
The shaded shape is a semicircle of diameter cm with semicircles of diameter cm and cm cut out along its diameter.
(a)[2 marks]Show that the perimeter of the shaded shape is cm.
(b)[3 marks]Work out the area of the shaded shape. Give your answer in terms of .
Answer(c)[2 marks]A circle has the same area as the shaded shape. Work out its circumference, to s.f.
AnswerTotal for D2: 7 marks
Extension
Grade 8 and beyondNo route is given. The hints are at the end of the sheet. Use one at a time.
- E1[4 marks]
A sector of a circle has radius cm. The perimeter of the sector is cm. Work out the area of the sector.
Hint 1 · What to try
Take the two radii off the perimeter. What is left is the arc.
Hint 2 · The first line
The arc is cm out of a whole circumference of cm. That fraction of the circle is the sector.
Hint 3 · The full method
Area . The cancels.
Answer cm
How did it go?
Colour one circle on each line.| Not yet | Nearly | Yes | |
|---|---|---|---|
| I can work out the circumference and area of a circle, and work back to the radius. | |||
| I can work out the arc length, perimeter and area of a sector, and its angle from them. | |||
| I can use circles and sectors in problems, giving answers in terms of when asked. |
Answers and mark scheme
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