1-5 Using Formulas in Geometry
Objective
SWBAT apply formulas for perimeter,
area, and circumference.
HW Pg 38{1,3,5,7,9,13,27,29,41,43,
EC 30}
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1-5 Using Formulas in Geometry
Vocabulary
perimeter
area
base
height
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diameter
radius
circumference
pi
1-5 Using Formulas in Geometry
The perimeter P of a figure is the
distance around it.
The area A of a figure is the
number of square units of a given
size that exactly cover the figure.
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1-5 Using Formulas in Geometry
Holt Geometry
1-5 Using Formulas in Geometry
The base b can be any side of a
triangle. The height h is a segment
from a vertex that forms a right angle
with a line containing the base.
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1-5 Using Formulas in Geometry
Remember!
Perimeter is expressed in linear
units, such as inches (in.) or meters
(m). Area is expressed in square
units, such as square centimeters
(cm2).
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1-5 Using Formulas in Geometry
Find the perimeter and area.
Holt Geometry
1-5 Using Formulas in Geometry
Find the perimeter and area.
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1-5 Using Formulas in Geometry
The perimeter of a circle has a special name,
circumference .
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1-5 Using Formulas in Geometry
Cherry pies, delicious!
C = d
Apple pies are too!
A = r2
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1-5 Using Formulas in Geometry
Example:
Find the circumference and area of a circle with
radius 8 cm. Leave your answer in terms of 
8cm
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1-5 Using Formulas in Geometry
Example:
Find the circumference of a circle whose area is
100 cm2. Leave your answer in terms of 
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1-5 Using Formulas in Geometry
Lesson Quiz: Part I
Find the area and perimeter of each figure.
1.
2.
x2 + 4x; 4x + 8
3.
10x; 4x + 16
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23.04 cm2;
19.2 cm
1-5 Using Formulas in Geometry
Lesson Quiz: Part II
Find the circumference and area of each circle.
Leave answers in terms of .
4. radius 2 cm 4² cm; 4 cm2
5. diameter 12 ft 362 ft; 12 ft2
6. The area of a rectangle is 74.82 in2, and the
length is 12.9 in. Find the width.
5.8 in
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