O is the centre of the circle in the given Figure ij OA =OB =OC The P.T.
∠x+∠y=2(∠z+∠t) x + y = angle subtended by chord AC at centre.
angle ABO = 90 - Z
angle CBO = 90 - T
angle ABO + angle CBO = 180 - (Z + T)
angle ABC = 180 - ( Z + T)
BUT angle ABC is angle in opposite segment of AC.=
12 Reflex (x + y)
180 - (z +T) =
12 (360 -(x +y)= 180 -
(x+y)2 z+t=(x+y)2 2(z + t) = (x + y) ---proved