Could you answer number 2? this is for geometry

108 degrees



Explanation:

Angle ABC is given to be 90 degrees. By the converse of Thales Theorem, we know that AC is a diameter of the circle. 
If we draw a line from A to C, it will pass through the center of the circle.

Therefore, arc AC is 180 degrees as this is half the distance around the circle.

minor arc AD = 72
minor arc CD = x
(minor arc AD) + (minor arc CD) = arc AC
72+x = 180
72+x-72 = 180-72
x = 108

minor arc CD is 108 degrees