Area - circles, sectors and segments

There are 32 NRICH Mathematical resources connected to Area - circles, sectors and segments
Mean Geometrically
problem
Favourite

Mean geometrically

Age
16 to 18
Challenge level
filled star filled star empty star
A and B are two points on a circle centre O. Tangents at A and B cut at C. CO cuts the circle at D. What is the relationship between areas of ADBO, ABO and ACBO?
Triangles and petals
problem
Favourite

Triangles and petals

Age
14 to 16
Challenge level
filled star filled star empty star
An equilateral triangle rotates around regular polygons and produces an outline like a flower. What are the perimeters of the different flowers?
Quadarc
problem
Favourite

Quadarc

Age
14 to 16
Challenge level
filled star filled star empty star
Given a square ABCD of sides 10 cm, and using the corners as centres, construct four quadrants with radius 10 cm each inside the square. The four arcs intersect at P, Q, R and S. Find the area enclosed by PQRS.
An Unusual Shape
problem
Favourite

An unusual shape

Age
11 to 14
Challenge level
filled star filled star empty star
Can you maximise the area available to a grazing goat?
Salinon
problem
Favourite

Salinon

Age
14 to 16
Challenge level
filled star empty star empty star
This shape comprises four semi-circles. What is the relationship between the area of the shaded region and the area of the circle on AB as diameter?
Compare Areas
problem
Favourite

Compare areas

Age
14 to 16
Challenge level
filled star filled star filled star
Which has the greatest area, a circle or a square, inscribed in an isosceles right angle triangle?
Spokes
problem
Favourite

Spokes

Age
16 to 18
Challenge level
filled star filled star filled star
Draw three equal line segments in a unit circle to divide the circle into four parts of equal area.
Gutter
problem
Favourite

Gutter

Age
14 to 16
Challenge level
filled star filled star empty star
Manufacturers need to minimise the amount of material used to make their product. What is the best cross-section for a gutter?
Blue and White
problem
Favourite

Blue and white

Age
11 to 14
Challenge level
filled star empty star empty star
Identical squares of side one unit contain some circles shaded blue. In which of the four examples is the shaded area greatest?
Partly Circles
problem
Favourite

Partly circles

Age
14 to 16
Challenge level
filled star filled star filled star
What is the same and what is different about these circle questions? What connections can you make?