13. 81.64
14. 803.84
15. 153.83
16. 753.6
you just use circumference and area formulas for a circle
70% equals to 70/100 in fraction form.
But, you need to write it in simplest form. so, divide both of them from 10 'cause they both can divide completely by it.
70/100 = 7/10
so, your answer is 7/10
First move the decimal by one and add a 0 and then a decimal after the 0.
then divide from there