McGraw Hill Integrated II, 2012
MH
McGraw Hill Integrated II, 2012 View details
3. Arcs and Chords
Continue to next subchapter

Exercise 52 Page 740

If a parallelogram is a rhombus, then it is symmetric about the diagonals.

28^(∘)

Practice makes perfect

We want to find the measure of ∠ YWZ, given that m∠ XZY=56^(∘). A rhombus is symmetric about its diagonals. Therefore ∠ XZY and ∠ YWX are congruent, which means they have the same measure.

In a rhombus, the diagonals bisect opposite angles. In our case the diagonal WZ bisects the angles ∠ YWX and ∠ XZY.

The measure of m∠ YWZ must be half the measure of m∠ YWX. With this information, we can write and solve an equation that contains m∠ YWZ.
m∠ YWZ=1/2m∠ YWX
m∠ YWZ=1/2( 56^(∘))
Evaluate right-hand side
m∠ YWZ=56^(∘)/2
m∠ YWZ=28^(∘)