McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
5. Rhombi and Squares
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Exercise 30 Page 518

The diagonals of a square bisects a pair of opposite angles.

m∠WYX=45

Practice makes perfect
We are given a square WXYZ and the point of intersection of the diagonals T. We want to find the measure of ∠ WYX. All four angles in a square are right angles. Let's begin by recalling that since each square is also a rhombus, each diagonal in a square bisects a pair of opposite angles.
Because the diagonal bisects ∠ XYZ, we know that m∠WYX is half of m∠XYZ. We also know that ∠ XYZ is a right angle, so its measure is 90^(∘). Let's calculate m∠ WYX by substituting 90 for m∠ XYZ.
m∠ WYX = 1/2* m∠ XYZ
m∠ WYX = 1/2* 90
m∠ WYX = 90/2
m∠ WYX = 45

Extra

Squares

Let's consider why the diagonals of a square bisect a pair of opposite angles. To do so, we will start by recalling and comparing the definitions of a square and a rhombus.

Type of Quadrilateral Definition
Square A square is a parallelogram with four congruent sides and four right angles.
Rhombus A rhombus is a parallelogram with four congruent sides.

We can see that the definition of a square contains the definition of a rhombus. Since a square is also a rhombus, all properties of rhombuses apply to squares.