geometry ch 11 vocab

parallelogram

• a quadrilateral with both pairs of opposite sides parallel

• the height of a parallelogram is the perpendicular distance between any two parallel bases

area of a region

the sum of the areas of its non-overlapping parts

area of a parallelogram

A=bh

area of a triangle

A=1/2(bh)

trapezoid

a quadrilateral with one pair of opposite sides parallel

area of a trapezoid

A=1/2(h)(b1+b2)

rhombus

a parallelogram with all sides congruent

kite

a quadrilateral with 2 sets of consecutive sides congruent

area for rhombus & kite

A=1/2(d1)(d2)

circumference

• the distance around the circle

• C=pi(d)

area of a circle

A=pi(r²)

sector

a region bound by a central angle and its intercepted major or minor arc (slice of pizza)

area of a sector

A/pi(r²) = x degrees/360

Heron’s Formula

A=square root of s(s-a)(s-b)(s-c)

s=semiperimeter=1/2(perimeter)

formula for if given two sides of a triangle and the included angle

A=1/2(ab)sin(C)

apothem

a segment drawn from the center of the regular polygon perpendicular to a side of the polygon

area of a regular n-gon

A=1/2(ap)