Chapter 8- Area Flashcards
Base
The length of the side the height is perpendicular to
Height
The length of an altitude
Rectangle area
A = bh
Parallelogram area
A = bh
Triangle area
A = 1/2bh
Trapezoid area
A = 1/2 (b1 + b2) h
Kite area
A = 1/2 (d1)(d2)
Apothem of a regular polygon
A perpendicular segment from the center of a polygons circumscribed circle to a side of the polygon
Area of a regular polygon formula
1/2asn
The apothem of a square is
Half the side length
Circle area
Formula derived by cutting the circle into wedges and arranging them into a rectangle
Circle area formula
A= π r^2
sector of a circle
the region between two radii and an arc of the circle
Asector=
a
__ x π r^2
360
Segment of a circle
the region between a chord and an arc of the circle
Asegment=
a
___ x π r^2 - 1/2bh
360
annulus of a circle
the region between two concentric circles
Aannulus=
πR^2 - πr^2
surface area
sum of the areas of all the faces or surfaces that enclose the solid
the lateral face of a prism is always
rectangular
a prism must have
2 congruent bases
SArectangularprism
2B + PH
B= area of base P= perimeter of base H= height
SAcylinder
2 π r^2 + 2 π r h
SApyramid
1/2abn + 1/2 lbn
or
1/2 aP + 1/2 lP
SAcone
πr^2 + πrl
