In the diagram at the right, YW bisects XYZ , and m XYW = 18 . Find m XYZ. o. By the Angle Addition Postulate, m XYZ = m XYW + m WYZ . Because YW bisects XYZ you know that XYW WYZ.
In the diagram at the right, YWbisects XYZ, and mXYW = 18. Find m XYZ.
By the Angle Addition Postulate, m XYZ =mXYW + m WYZ. BecauseYW bisects XYZyou know thatXYW WYZ.
So, m XYW = m WYZ, and you can write
m XYZ = m XYW + m WYZ = 18° + 18° = 36°.
Double an angle measure
for Example 5
7. Angle MNPis a straight angle, and NQbisects MNP. Draw MNP And NQ. Use arcs to mark the congruent angles in your diagram, and give the angle measures of these congruent angles.