1. A quadrilateral with only one pair of parallel sides.
The parallel sides of the trapezoid.
The angles formed by the bases and legs of a trapezoid.
The non-parallel sides of a trapezoid.

2. A trapezoid with congruent legs.
Segment connecting the midpoints of the legs.
A quadrilateral that has two pairs of consecutive congruent sides, but opposite sides are not congruent.

3. 4 - 3
_____
4 - 1 1 __ 3
2 - 0
_____
6 - 0 2 __ 6 1 3 ∥
2 - 4
_____
6 - 4 -2 __ 2 -1
3 - 0
_____
1 - 0 3 __ 1
not parallel
parallel sides

4. Isosceles Trapezoid Theorem
congruent
D B
Converse of Isosceles Trapezoid Theorem
base angles
Diagonals of Isosceles Trapezoid Theorem
congruent
AC DB

5. isosceles trapezoid K
K °
supplementary
180° ° ° L
L °
50° ° °

6. E (7, 5)
mDE =
5 - 3
_____
7 - 1 1 __ 3 =
mCF =
2 - 0
6 - 0
mCD =
1 - 0
3 - 0
= 3
mEF =
5 - 2
7 - 6
Quadrilateral CDEF is a parallelogram because the opposite sides are parallel.
m∠C = m∠B = 135°
m∠A = 180° - m∠B
m∠A = 180° - 135°
m∠A = 45°
m∠D = m∠A = 45°

7. 1 __ 2
AB CD
AB CD
A = 1 __ 2
(b1 + b2)
b1 & b2 are the bases of the trapezoid

8. 1/2 PQ SR 1/ 16 9
12.5

9. MN = 1/2(b1 + b2)
MN = 1/2( )
MN = 1/2(42)
MN = 21ft

10. perpendicular
AC BD ≅ ≅

11. congruent R R
m∠S m∠Q °
88° ° °
° °
2m∠T = 202°
101°

12. m∠G + m∠I + m∠H + m∠J = 360°
m∠G + m∠G + 85° + 75° = 360°
2m∠G + 160° = 360°
2m∠G = 200°
m∠G = 100°