Circle P has tangents XY and ZY and chords WX and WZ. The measure of angle ZWX=70 degrees. What is the measure in degrees of angles XYZ?

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1 Answer
Oct 3, 2017

#angleXYZ = 40^@#

Explanation:

We are given:

#angleZWX = 70^@#

This means that the central angle is:

#angleZPX = 140^@#

The radii of the central angle form right angles with the tangents:

#anglePZY = anglePXY = 90^@#

#PZYX# forms a quadrilateral, therefore, the some of the internal angles are:

#360^@= angleZPX + anglePZY + anglePXY + angleXYZ#

Substituting in the values:

#360^@= 140^@ + 90^@ + 90^@ + angleXYZ#

#angleXYZ = 40^@#