don't even know how to begin, does it involve factor/sum formulae?
angle ABC and angle ADC is 90 deg respectively. because AC is diameter.
angle BAD is 180deg-θ°. because of cyclic quadrilateral.....
how do i relate them and find AD?
sin x cos x = -(3/10)
then ....can i do this :
sin x = - (3/10) , cos x = - (3/10)
??? or i can only do this when it's equal to zero?
what i tried to do:
thus, i roughly know it would be something like (x^2)+(y^2).....
and then......i'm stuck ="=
how am i going to find the radius ...
and the question never mention about radius/diameter...