Try some yourself

Answer

• (a)

  

• (b)

  

Answer

• (a) Area = 10 m × 6 m = 60 m².

• (b) Area = (1.1 m)² ≈ 3.80 m².

• (c) Area =  × 10m × 5m = 25m².

Answer

Add together the areas of the rectangle and the triangle from Question 2, and subtract the area of the circle to find

Answer

In the following calculation, full calculator accuracy numbers are indicated by three dots. For example the full calculator accuracy value for is written as 3.141 ... .

There are four slabs in this circle, so each slab will have a

The surface area of the eight slabs in the inner ring is calculated by subtracting the central circle from the circle with radius 0.8 m:

There are eight slabs in the inner ring, so each slab will have a

Use a similar method to find the surface area of the outer ring of slabs:

There are sixteen slabs in the inner ring, so each slab will have a

Assuming that the slabs are of equal thickness, and are made of the same material, the weights of the slabs will be proportional to the surface areas. So the results show that the lightest slabs are in the central circle and the heaviest in the inner ring.