001 area, perimeter
TRANSCRIPT
Geometry Drill 4/8/13
In your own words define
perimeter and area
Make a list of any formula you
know that applies to perimeter or
area of a geometric figure.
April is Math Month
Geometry
Find the distance
between points
A(1,4) and B(-3,9)
Objective
SW recall area and
perimeter formulas so
that they can find the
area and perimeter of
irregular regions.
Compare:
Regular polygons vs.
polygons
Perimeter of a Rectangle
P=2b+2hh
b
Area of a Rectangle
A=bhh
b
Area of a Triangle
A=(1/2)bhh
b
Irregular Region
A region(shape)
composed of many
smaller
regions(shapes)
Area of an Irregular Region
The sum of the areas
of all the non-
overlapping parts of
the region
Find the area of the irregular region
43
2
Perimeter of an Irregular Region
The distance
around the
region.
Find the Perimeter of the region
43
2
Conclusions1) To find the area of an
irregular region, find the
areas of its smaller
_____ and find their
_____.
Conclusions1) To find the area of an
irregular region, find the
areas of its smaller
_____ and find their
_____.
parts
sum
Conclusions2) To find the perimeter
of an irregular region,
find the ________
around the region.
Conclusions2) To find the perimeter
of an irregular region,
find the ________
around the region.distance
Find the perimeter of
rectangle ABCD
A
BC
D
5 in.
3 in.
4 in.
EXPLORATIONWe know how to find
the area of a rectangle.
How can I form a
rectangle from this
parallelogram?
Parallelogram
Parallelogram
Parallelogram
Parallelogram
Parallelogram
Parallelogram
Rectangle
b2
b2
b1
b1
h
h
b2
b2
b1
b1
h
h
b2
b1
hb2
b1
h
b2
b1
h
b2
b1
h
b2
b1
h
Parallelogram
b1
b2
AREA OF A PARALLELOGRAM
A = bh
Find the area:
8
57
Find the area:
5
42
AREA OF A TRIANGLEA = 1/2(bh)
Find the area:
10
56
Find the area:
12
915
AREA OF A TRAPEZOIDA = h/2(b1+b2)
b1 and b2 are the
bases
Find the area:
5
12
8
ALTERNATE FORMULA AREA OF A TRAPEZOIDA = length of
median times the
height
Find the Area of Trapezoid ABCD
12
10
ABCD is a rhombus withdiagonals d1 & d2
D C
A B
AREA OF A RHOMBUSA = 1/2(d1d2)
d1 and d2 are the
diagonals
Area of a RhombusFind the area of a
rhombus if the lengths
of the diagonals are
12m and 10 m.