I need help with my math work please help

Given that ot =5, xt=12, and ox= 13 is xy tangent to circle o at t? explain.

Acircle has a circumference of 28.36 units what is the diameter of the circle

Graph the line that represents a proportional relationship between d and t with the property that an increase of 33 units in t corresponds to an increase of 44 units in d. what is the unit rate of change of dd with respect to t? (that is, a change of 11 unit in t will correspond to a change of how many units in d? )