Find the sum of the measure of the interior angles of a convex 70-gon

Ageologist had two rocks on a scale that weighed 4.6 kilograms together.rock a was 0.5 of the total weight.how much did rock a weigh?

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.

Jimmy can run 3.5 miles in 20 minutes. how far can ne run in one hour and ten minutes?