a) Find the area of a semi circle with diameter 12cm. b) The area of a semi-circle is 60cm^2. Find the radius of the sem-circle.
a) radius = 12/2 = 6cm. Area of a circle = pi x r^2 = 36pi. Area of semi-circle = 36pi / 2 = 18pi cm^2b) Area of full circle = 120. pi x r^2 = 120. r^2 = 120/pi. r = sqr root (120/pi)= 6.18cm
AG
Related Maths GCSE answers
All answers ▸I want to buy 1 litre of milk. My options are to either buy 250ml bottles for £1 each or 500ml bottles for £1.50 each. Which is the cheapest way for me to buy 1 litre of milk?
What is the significance of the number e (Euler's number)?
The are 10 coloured balls in a bag, 4 red, 3 green, 2 orange and 1 yellow. John picks out balls and replaces them one at a time. What is the probability that the first two he picks are red?
How do tree diagrams work? Consider: A bag contains 5 red counters and 3 blue counters. James draws a counter from the bag at random and keeps it. James then draws a second counter at random. What is the probability that James takes two red counters?