Day 1 Area Notes.notebook
April 20, 2015
Do Now
What is the difference between the perimeter and the area of a shape?
Area
Objective: G‐ GPE.B.7
Day 1 Area Notes.notebook
April 20, 2015
Area
• The number of square units contained
within the figure
s
s
s
Area of a
square = s2
s
4in
4in
4in
4in
Area = (4in)2
=16 sq. in.
Day 1 Area Notes.notebook
April 20, 2015
L
W
W
Area of a
rectangle = LW
2ft
Area = 4ft 2ft
= 8 sq. ft.
L
4ft
●
2ft
4ft
height
Area of a
parallelogram = bh
base
In a parallelogram, the base is a side and the height
(or altitude) is a segment drawn perpendicular to the
base from the opposite vertex
3 cm
6 cm
5cm
Area = 3 cm 6cm
= 18 cm2
●
(parallelogram - both pairs of opposite sides are parallel)
Day 1 Area Notes.notebook
height
April 20, 2015
Area of a
rhombus = bh
2m
base
5m
Area = 5m 2m
= 10 m2
●
(rhombus - parallelogram in which all sides are equal lengths)
Area of a
triangle = ½bh
Area = ½ 5in 4in
= ½ 20in2
= 10 in2
● 4in
●
5in
●
Day 1 Area Notes.notebook
base1
height
April 20, 2015
Area of a
trapezoid = ½h(b1 + b2)
base2
2 mm
3 mm
Area = ½2mm(3mm +7mm)
=1mm(10mm) = 10 mm2
7 mm
(trapezoid - two and only two opposite sides are parallel)
Isosceles Trapezoid ­ A trapezoid in which non­
parallel sides and base angles are equal is called as an Isosceles Trapezoid
Day 1 Area Notes.notebook
April 20, 2015
Area of a
circle = πr2
Formulas
A = LW
C = 2πr
Square
Rectangle
Circle
Rhombus
Trapezoid
Parallelogram
A = bh
P =4s
A = bh
A = ½bh
A = πr2
A = s2
A = ½h(b1 + b2)
P = 2L +2W
Triangle
Day 1 Area Notes.notebook
April 20, 2015
Match each formula on the left with the area it represents.
______ 1) bh
______ 2) ½h(b1 + b2)
______ 3) s2
______ 4) ½bh
______ 5) πr2
______ 6) lw
Identify Shape:
Area Formula:
a) area of a square
b) area of a circle
c) area of a parallelogram
d) area of a rectangle
e) area of a trapezoid
f) area of a triangle
Day 1 Area Notes.notebook
Identify Shape:
Area Formula:
Identify Shape:
Area Formula:
April 20, 2015
Day 1 Area Notes.notebook
April 20, 2015
Identify Shape:
Area Formula:
Identify Shape:
Area Formula:
11
Fix measure
Day 1 Area Notes.notebook
April 20, 2015
Identify Shape:
Area Formula:
2
3
Fix measure
Identify Shape:
Area Formula:
Day 1 Area Notes.notebook
April 20, 2015
Identify Shape:
Area Formula:
Exit Ticket:
How many formulas do you already have memorized? Write them down with the shape.