unit 10 review area formulas. for each figure: imagine the shape think of its area formula
TRANSCRIPT
Unit 10 Review
Area Formulas
FOR EACH FIGURE:
• IMAGINE the shape
• THINK of its AREA FORMULA
The “base” of the polygon does not need to be on the
bottom!
!The HEIGHT of the polygon does not need to be vertical!
The base and height must bePERPENDICULAR to each
other!
RECTANGLE
A = bh
A=bh
The base and height must be perpendicular to each other.
h
b
PARALLELOGRAM
A = bh
A=bh
The base and height must be perpendicular to each other. The height can be outside the figure.
h
b
SQUARE
A = s2
A = bh
All 4 sides are congruent.
A=bh becomes A=s2
s
s
TRIANGLE
A =
A =
The base and height must be perpendicular.
base b
h
TRAPEZOID
A =
A =
The bases are parallel.
b1
b2
h
RHOMBUS
A =
A =
Don’t add the diagonals. MULTIPLY the diagonals.
KITE
A =
A =
Don’t add the diagonals. MULTIPLY the diagonals.
REGULAR POLYGON
A =
A =
To find the central angle, divide 360 by the number of sides.
A =
Apothem = a Perimeter = p
a
Bonus: Triangle given SAS
A =
A =
a
C b
Circle Area
A =
A =The radius is half of the diameter.
r
CIRCUMFERENCE
C = C =
C = C =
r
Quick Check:
Circle Area
A =
REGULAR POLYGON
A =
TRAPEZOID
A =
KITE
A =
SQUARE
A = s2
A = bh
PARALLELOGRAM
A = bh
CIRCUMFERENCE
C = C =
RHOMBUS
A =
TRIANGLE
A =
RECTANGLE
A = bh
Triangle