write in standard form

the smaller semi circle can fill in the empty space on the 10cm radius. this makes it easier to work out the answer as you only have to work out one big semicircle. so first to work out the area of the circle is = 3.142 x radius^2

TO Work out the semi circle +

to work out the semi circle= 3.142 x radius^2 and then divide the answer by 2. so 3.142 x 10^2 which is 3.142 x 100 = 314.2 314.2 divide by 2 = 157.1 THE ANSWER IS 157.1