Question

URGENTLY REQUIRED



In the given figure, M, A, B and N are points on a circle having centre O. AN and
MB cut at Y. If NYB = 50° and YNB = 20°, then reflex MON is equal to

Answer 1

Answer:

(write given and Required to prove)

Proof:

in triangle YBN,

∠YBN + ∠BNY + ∠NYB = 180° (angle sum property)

substituting the values,

∠YBN + 20° + 50° = 180°

∠YBN + 70° = 180°

∠YBN = 110°

by using the theorem (angle subtended by the arc is double the angle subtended by it on any part of the circle),

therefore, ∠MON = 2 * ∠YBN

so, reflex ∠MON = 220°

(Please let me know if it is correct)