Factors of 7 are 1 and 7 and that's it because it is prime number and the 5 multiples are 1,2,3,4,5 2,4,6,8,10 3,6,9,12,15 4,8,12,16,20 5,10,15,20,25 6,12,18,24,30 7,14,21,28,35 8,16,24,32,40 9,18,27,36,45 10,20,30,40,50
To find the area of a circle you use the formula A = π · r²
So we know that the diameter is 28 cm, to find the radius we would divide this in half, because d = 2r, giving us 14. Now we can do 14² which is 196, and then times that by pi or in this case 22/7.
