For the values a = 7.2 which is a leg of a right triangle, and value c = 11.1, which is the hypotenuse, find the length of the other leg, b, to the nearest tenth

1. what is the measure of ∠abc? what is the measure of ∠abd?

15/16 as a decimal rounded to the nearest hundredth

Offering 30 if a plus b plus c equals 68 and ab plus bc plus ca equals 1121, where a, b, and c are all prime numbers, find the value of abc. the answer is 1978 but i need an explanation on how to get that.