Lesson 10-5 Identify and Classify Quadrilaterals

Quadrilateral A closed figure with four sides and four angles. Quadrilaterals are named based on their sides and angles. The diagram shows how the quadrilaterals are related.

Quadrilateral

Parallelogram Means parallel Means congruent A quadrilateral with opposite sides parallel and opposite sides congruent.

Rectangle A parallelogram with 4 right angles.

Rhombus A parallelogram with 4 congruent sides.

Square A parallelogram with 4 right angles and 4 congruent sides.

Trapezoid A Quadrilateral with one pair of parallel sides.

Quadrilateral Parallelogram Rhombus Trapezoid Rectangle Square

Measure of a Quadrilateral B A A Quadrilateral can be separated into 2 triangles. Since the sum of the measure of each triangle is 180° then the sum of the measure of both triangles is 180 +180 = 360° The sum of the measure of the angles of a quadrilateral is 360°

Find the measure of the missing angle. 85 + 73 + 59 = 217 360 – 217 = x = 143° 73° 59° 85° x°

Concept Check Explain why all squares are rectangles but not all rectangles are squares?

Concept Check A quadrilateral is a trapezoid. Always Sometimes Never

Concept Check A quadrilateral is a trapezoid. Always Sometimes Never

Concept Check A parallelogram is a rectangle. Always Sometimes Never

Concept Check A parallelogram is a rectangle. Always Sometimes Never

Concept Check A trapezoid is a parallelogram. Always Sometimes Never

Concept Check A trapezoid is a parallelogram. Always Sometimes Never

Practice Work Classwork - Old Blue p. 435 - 437 (4-25, 28-37, 39-50) IXL Lesson P8 Homework - Practice worksheets