In the figure, XY=6 cm, ∠XOY=∠MON=85∘. The length of the chord MN is
It is given that ∠XOY=∠MON.
Consider ΔXOY and ΔMON,
Here,
OX=OM= radius of the circle
OY=ON= radius of the circle
and ∠XOY=∠MON=85∘ [given]
∴ΔXOY≅ΔMON [by SAS criterion]
∴XY=MN [CPCT]
⇒MN=XY=6 cm.