Chapter 5

Question 1

parallelogram

Answer 1

a quadrilateral with both pairs of opposite sides parallel

Question 2

theorem 5-1

Answer 2

opposite sides of a parallelogram are congruent

Question 3

theorem 5-2

Answer 3

opposite angles of a parallelogram are congruent

Question 4

theorem 5-3

Answer 4

diagonals of a parallelogram bisect each other

Question 5

theorem 5-4

Answer 5

if both pairs of opposite sides of a quadrilateral are congruent, then the quadrilateral is a parallelogram

Question 6

theorem 5-5

Answer 6

if one pair of opposite sides of a quadrilateral are both congruent and parallel, then the quadrilateral is a parallelogram

Question 7

theorem 5-6

Answer 7

if both pairs of opposite angles of a quadrilateral are congruent, then the quadrilateral is a parallelogram

Question 8

theorem 5-7

Answer 8

if the diagonals of a quadrilateral bisect each other, then the quadrilateral is a parallelogram

Question 9

five ways to prove that a quadrilateral is a parallelogram

Answer 9

1. show that both pairs of opposite sides are parallel
2. show that both pairs of opposite sides are congruent
3. show that one pair of opposite sides are congruent and parallel
4. show that both pairs of opposite angles are congruent
5. show that the diagonals bisect each other

Question 10

trapezoid

Answer 10

quadrilateral with exactly one pair of parallel sides

Question 11

bases

Answer 11

parallel sides of a trapezoid

Question 12

legs

Answer 12

other sides of the trapezoid

Question 13

isosceles trapezoid

Answer 13

a trapezoid with congruent legs

Question 14

theorem 5-18

Answer 14

base angles of an isosceles trapezoid are congruent

Question 15

median of a trapezoid

Answer 15

segment that joins the midpoints of the legs

Question 16

theorem 5-19

Answer 16

the median of a trapezoid:

• is parallel to the bases
• has a length equal to the average of the base lengths