In the figure, YX and YZ are tangents to circle A at points X and Z, respectively.

measure of arc XZ= 140 measure of arc XSZ= 220

What is the measure of ∠XYZ ?

When we have two tangents drawn to a circle as above....it sets up the following :

measure XYZ = (1/2) (arc XSZ - arc XZ ) =

(1/2) ( 220 - 140 ) =

(1/ 2) ( 80) =

40°