310 likes | 428 Views
This chapter covers the essential properties and types of quadrilaterals, which are closed geometric figures with four sides and vertices. It introduces the concept of diagonals, the sum of interior angles, and focuses on specific types of quadrilaterals like parallelograms, rectangles, rhombi, and trapezoids. Key theorems are presented, highlighting characteristics such as congruent sides and angles, parallelism, and bisection of diagonals. The relationships between different quadrilaterals are illuminated, providing a comprehensive framework for understanding these geometric shapes.
E N D
Chapter 8 Quadrilaterals
Section 8-1 Quadrilaterals
A closed geometric figure with four sides and four vertices. Quadrilateral
Any two sides, vertices, or angles of a quadrilateral are either consecutive or nonconsecutive.
Segments whose endpoints are nonconsecutive vertices of a quadrilateral Diagonals
The sum of the measures of the angles of a quadrilateral is 360°. Theorem 8-1
Section 8-2 Parallelograms
A quadrilateral with two pairs of parallel sides Parallelogram
Opposite angles of a parallelogram are congruent. Theorem 8-2
Opposite sides of a parallelogram are congruent. Theorem 8-3
The consecutive angles of a parallelogram are supplementary. Theorem 8-4
The diagonals of a parallelogram bisect each other. Theorem 8-5
The diagonal of a parallelogram separates it into two congruent triangles. Theorem 8-6
Section 8-3 Tests for Parallelograms
If both pairs of opposite sides of a quadrilateral are congruent, then the quadrilateral is a parallelogram. Theorem 8-7
If one pair of opposite sides of a quadrilateral is parallel and congruent, then the quadrilateral is a parallelogram. Theorem 8-8
If the diagonals of a quadrilateral bisect each other, then the quadrilateral is a parallelogram. Theorem 8-9
Section 8-4 Rectangles, Rhombi, & Squares
A parallelogram with 4 right angles Rectangle
A parallelogram with 4 congruent sides and 4 right angles Square
The diagonals of a rectangle are congruent Theorem 8-10
The diagonals of a rhombus are perpendicular Theorem 8-11
Each diagonal of a rhombus bisects a pair of opposite angles Theorem 8-12
Section 8-5 Trapezoids
The parallel sides are called bases • The nonparallel sides are called legs Bases and Legs
Each trapezoid has two pairs of base angles Base Angles
The median of a trapezoid is parallel to the bases, and the length of the median equals one-half the sum of the lengths of the bases. Theorem 8-13
Each pair of base angles in an isosceles trapezoid is congruent. Theorem 8-14