The points A, B, C and D lie on a circle centre O. Angle AOB = 90° angle COD= 50° and angle BCD= 1239
The line DT is a tangent to the circle at D.
Find
(a) angle OCD

in the attachment.   i didn't see your choices.   the word which means there is choices.

step-by-step explanation:

(x,y)

x tells you how much left or right you go from the origin

y tells you how much down or up you go from the origin

so for example (-3,2), you go left 3 and up twice. i denoted which of the ordered pairs is which in my graph.