Geometry of shapes

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3

<C & <D = pair of base angles

Slide 16

Trapezoids (3)

Isosceles trapezoid: A trapezoid with congruent legs.

Theorem 6-14: Both pairs of base angles of an isosceles trapezoid are congruent.

Theorem 6-15: The diagonals of an isosceles trapezoid are congruent.

Slide 17

Trapezoids (4)

C

A

C

D

B

The median of a trapezoid is the segment that joints the midpoints of the legs (PQ).

Q

P

Theorem 6-16: The median of a trapezoid is parallel to the bases, and its measure is one-half the sum of the measures of its bases.

Slide 18

Area of Trapezoids

C

A

C

D

B

Area of a trapezoid: If a trapezoid has an area of A square units, bases of b1 and b2 units and height of h units, then A = ½(b1 + b2 )h.

h