Level 3
The figure is make up of 3 circles. The small circle has centre O and a radius of 6 cm. The big circle, has centre O and a radius of 10 cm. The diameter of the big circle cuts through the centre of the medium-sized circle and the small circle. The three regions formed are indicated as X, Y and Z.
  1. Find the radius of the medium-sized circle.
  2. Find the area of region Z. Use a calculator to obtain the value of π. (Round off to nearest 2 decimal places).
  3. Express the area of the region Y as a ratio to the area of region X.
5 m
Level 3
The figure is made up of a circle, a rectangle and 2 semicircles. AC, the diameter of the circle, is 15 cm, AB is 12 cm and BC is 9 cm.
  1. What is the total area of the shaded parts?
  2. What is the total perimeter of the shaded parts? (Take π = 3.14)
5 m
Level 3 PSLE
A small circle with centre O has been cut from a circular piece of cardboard with the same centre. The radius of the small circle is 8 cm.
The remaining cardboard is then cut into four equal parts along the dotted lines as shown in Figure 1. The four parts are rearranged to form a new shape in Figure 2.
  1. Find the area of the new shape.
  2. Find the perimeter of the new shape. (Take π = 3.14)
5 m