6 5 Trapezoids A Trapezoid a quadrilateral with
- Slides: 10
6. 5 Trapezoids A Trapezoid - a quadrilateral with: *one pair of parallel sides (called bases) *two pairs of base angles *one pair of nonparallel sides (called legs) If legs are congruent – isosceles trapezoid B A C D
Ex 1: Given Trapezoid ABCD with , identify the segments or angles as bases, consecutive sides, legs, diagonals, base angles, or opposite angles. C B consecutive c) sides A D d) a) bases b) legs e) f) diagonals opposite angles base angles
Thm 6. 14 – If a trapezoid is isosceles, then each pair of base angles is congruent. B C A D Thm 6. 15 – If a trapezoid has a pair of congruent base angles, then it is isosceles. B A C D
Thm 6. 16 – A trapezoid is isosceles iff its diagonals are congruent. B A If C D , then Trapezoid ABCD is isosceles.
Ex 2: Given isosceles trapezoid PQRS, find and. S R 50° P Q The trapezoid is isosceles, so base angles are congruent (the measures are equal). are consecutive, hence supplementary.
Ex 2: Given isosceles trapezoid PQRS, find and. S R 50° P Q Again, base angles in an isosceles trap are congruent!
Recall, the midsegment of a triangle joins the midpoints of the sides. For a trapezoid, it joins the midpoints of the trapezoid’s legs. midsegment Click on the link. Read up to the formula to determine the length of a trapezoid’s midsegment: http: //www. mathopenref. com/trapezoidmedian. html Proceed with the Power. Point when finished.
Ex 3: Find the length of midsegment N. M 8 m A O B 20 m P
Ex 4: Find x. A E D 8 B 9 F x C Multiply both sides by 2 to get rid of the fraction
Assignment Page 359 #10 – 24 *ask for your handout on 6. 5 once you’ve gotten to this slide
