Help i don’t understand!!

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angle measure.

The table below shows the approximate height of an object x seconds after the object was dropped. the function h(x)= -16x^2 +100 models the data in the table. for which value of x would this model make it the least sense to use? a. -2.75 b. 0.25 c. 1.75 d. 2.25

Which term describes the point where the perpendicular bisectors of the three sides of a triangle intersect?