Download Lesson 8-6 Notes

Geometry Chapter 8-6 notes
Trapezoids
Lesson 8-6 OBJECTIVE:
SWBAT recognize and apply properties of trapezoids and solve problems involving medians of trapezoids. A _________________ is a quadrilateral with exactly one pair of parallel sides. The parallel
sides are called bases. The base angles are formed by a base and one of the legs. The
nonparallel sides are called legs.
If the legs of a trapezoid are congruent, then the trapezoid is an ______________________.
There are 2 characteristics of isosceles trapezoids.
Example #1
JKLM is a quadrilateral with vertices J(-18, -1); K(-6,8); L(18,1), and M(-18,-26).
a. Verify that JKLM is a trapezoid. Hint: Find
the slope of all 4 sides.
JK = -9/-12 = ¾
KL = 7/-24
JM = -25/0 = undefined
ML = 27/36 = ¾
b. Determine whether JKLM is an isosceles
trapezoid. Hint: Find the length of the legs.
The segment that joins midpoints of the legs of a trapezoid is the ______. The median of a
trapezoid can also be called a ________.
Two characteristics that apply to medians of a trapezoid. EXAMPLE: EF = 1/2(AB + DC)
Example #2
QRST is an isosceles trapezoid with
median XY.
a. Find TS is QR = 22 and XY = 15.
b. Find m∠1, m∠2, m∠3, and m∠4 if
m∠1 = 4a - 10 and m∠3 = 3a + 32.5.