You used properties of parallelograms and determined whether quadrilaterals were parallelograms.

• Recognize and apply properties of rectangles.

• Determine whether parallelograms are rectangles.

A. x = 1

B. x = 3

C. x = 5

D. x = 10

Quadrilateral EFGH is a rectangle. If mFGE = 6x – 5 and mHFE = 4x – 5, find x.

Rectangles and Coordinate Geometry

Quadrilateral JKLM has vertices J(–2, 3), K(1, 4), L(3, –2), and M(0, –3). Determine whether JKLM is a rectangle using the Distance Formula.

Step 1 Use the Distance Formula to determinewhether JKLM is a parallelogram bydetermining if opposite sides are congruent.

Rectangles and Coordinate Geometry

Since opposite sides of a quadrilateral have the same measure, they are congruent. So, quadrilateral JKLM is a parallelogram.

Rectangles and Coordinate Geometry

Answer: Since the diagonals have the same measure, they are congruent. So JKLM is a rectangle.

Step 2 Determine whether the diagonals of JKLMare congruent.