In the diagram , AOB is a diameter of the circle with centre O . ACX , BDY and DEC are tangents to the circle at A , B and E respectively . Show that
(1) angle COD =90
(2) OC . OD = 1/2 AB . CD
Hello thereddevilsPart (1) is like your previous question: Geometry (1). Here's the outline of the proof. I'll leave the details to you. Let .
Then and (congruent 's)
Then look at the quadrilateral . Can you see why ? Hence . Then look at , and you're there.
Part (2) Let .
Then look at the areas:
Grandad