Please Answer Questions 4 and 5

Decide whether the numbers can represent the side lengths of a triangle. If they can, classify the triangle as acute, right, or obtuse

Don't know how to find x given these segment lengths

Suppose that sahil knows that 45 people with ages of 18 to 29 voted. without using a calculator, he quickly says then 135 people with ages of 30to 49 voted. is he correct? how might sohil have come up with his answer so quickly?

In the diagram, ab is tangent to c, ab = 4 inches, and ad = 2 inches. find the radius of the circle.