Perimeter, Area and Volume of Regular Shapes - University of Exeter
Camborne School of Mines
Perimeter, Area and Volume of Regular Shapes
University of Exeter
Perimeter of Regular Polygons Perimeter means the total length of all sides, or distance around the edge of a polygon.
For a polygon with straight sides this is the sum of all sides.
Eg. triangle
rectangle
parallelogram
trapezium
8
11
9
5
5
6
6
7
7
4
4
4
11
5 + 5 + 4 = 14cm 6 + 6 + 11 + 11 = 34cm All dimensions given in cm (not drawn to scale)
8
8 + 8 + 7 + = 30cm
3
4 + 4 +9 + 3 = 20cm
For polygons with curved sides the perimeter is known as the circumference and is given by the formula
Circumference = 2r for a circle and
2 a? + b? for an ellipse 2
Where
is a mathematical constant with the value of 3.142 (correct to 3 decimal places)
r is the radius of the circle (distance from centre to circumference)
a is the major radius of an ellipse ................
b is the minor radius of an ellipse .._.._.._.._.._
Eg.
a = 6cm
b = 4cm
Circumference = 2r
2 x 3.142 x 5
31.42cm
circumference = 2 x 3.142 36 + 16
2
radius = 5
= 32.04cm
Area of Regular Polygons The area of a polygon is the space it occupies in a single plane.
For squares, rectangles and parallelograms the area is given by
Area = base x height
Eg.
12
4
ht = 7
12
12
8
12 x 12 = 144cm?
12 x 4 = 48cm?
8 x 7 = 56cm?
Height is defined as the perpendicular distance between the pair of parallel sides
ELE Page
CSM1027 Maths 1A Foundation
Camborne School of Mines
All dimensions given in cm (not drawn to scale)
For Triangles
area = ? x base x height
University of Exeter
Where height is distance from apex to meet base at right angle
Area = ? x 12 x 3 = 18cm?
3 cm
For Trapeziums
12 cm
area = ? sum of parallel sides x height
8 cm
7 cm
Area = ? x (8 + 14) x 7 = 77cm?
For Circles
14 cm
area = r?
r = 5
Area = r? = 3.142 x 5? = 78.54cm?
For a sector of a Circle
r = 5 60?
area = area of circle x sector angle 360
Area of sector = r? x 60 = 13.1cm? 360
For Ellipse
b = 5
a = 5
area = ab
Area = 3.142 x 10 x 5 = 157cm?
Complex shapes for which there are no formulas should be divided into simple shapes. The area of each is then calculated and added together to determine the overall area.
A1 A5 A3
A2
ELE Page
Area = A1 + A2 + A3 + A4 - A5
A4
CSM1027 Maths 1A Foundation
Camborne School of Mines
University of Exeter
Volume of Regular Shapes
Volume is the amount of space in 3 dimensions occupied by a shape.
Prism A prism is any shape where the cross-sectional area is constant.
For any prism:
Volume
= area of base x height
Rectangular Prism
h
b I Shaded area is the base
area of base =
volume
=
length x breadth length x breadth x height
eg. calculate the volume of a block with a square base of side 6cm and a height of 10cm
volume
= 1 x b x h = 6 x 6 x 10 = 360cm?
Triangular Prism
h1
h2
b
Shaded area is the base
Circular Prism
h r Shaded area is the base
ELE Page
area of base =
volume
=
? x base x height ? x base x h1 x h2
eg. determine the volume of a component 16cm long with a triangular cross-section which has a base of 4cm and perpendicular height of 5cm
area of base =
volume
=
=
? x 4 x 5 ? x 4 x 5 x 16 160cm?
area of base =
volume
=
r? r? x height
eg. calculate the volume of a cylinder with a radius of 5cm and a height of 4cm.
volume
= r? x height = 3.142 x 5? x 4 = 314.2cm?
CSM1027 Maths 1A Foundation
Camborne School of Mines
University of Exeter
The volume of certain non-prismatic shapes can be determined by using the correct formula.
Sphere r
volume of a sphere =
4 r3 3
eg. determine the volume of a spherical component with the radius of 7cm.
Pyramid and cone
volume
= 4 x 3.142 x 7? = 1436.76cm? 3
h b
1
h r
volume
Pyramid volume
Cone volume
= 1 x base area x height 3
= 1x1xbxh 3
= 1 x r? x h 3
eg. calculate the volume of a cone with base radius of 6cm and perpendicular height of 10cm
Volume
= 1 x 3.142 x 6? x 10 = 376.00cm?
3
Volumes of irregular shapes can be determined by calculation if the mass and density of the
material from which it is known or by displacement.
Calculation of volume using density and mass.
eg. density of substance from which an irregular object is made is 8500kg/m?. if it has a mass of 425kg, calculate its volume.
Volume
=
mass
density
= 425 = 0.05m? 8500
Measurement of volume using displacement
500cc 2nd reading
300cc
1st reading
volume
= 2nd reading ? 1st reading = 500 ? 300 = 200cc
Measuring cylinder
ELE Page
CSM1027 Maths 1A Foundation
Camborne School of Mines
University of Exeter
Perimeter, Area and Volume of Regular Shapes Worksheet 1
Calculate the area of the following shapes
1.
2.
15 cm
9.5 cm
5 cm
3.
15 cm
4.
1.3 cm
7.8 cm
4.5 cm 6 cm
1.3 cm
3 cm
5.
3.5 cm
12 cm 12 cm
47.5 cm
2.5 cm
24 cm
5 cm
6. A water tank is a cuboid with a base of 1.2m by 0.8m. How deep is the water when the tank contains 0.384m? of water?
7. A classroom is 5m x 6m x 3m. Health regulations require that each student must have a minimum of 5m? of air. How many students can occupy the room?
Calculate the volume of the following shapes. All dimensions in cm.
8. 2 2
9.
2
10.
12
8
15
2 6
Internal r = 0.75 External r = 1.00
ELE Page
CSM1027 Maths 1A Foundation
................
................
In order to avoid copyright disputes, this page is only a partial summary.
To fulfill the demand for quickly locating and searching documents.
It is intelligent file search solution for home and business.
Related download
- volume of cylinder
- perimeter area and volume of regular shapes university of exeter
- composite volume
- surface area of composite figures ms ong s math class
- significant figures and measurement of density
- 4 3 volumes of solids opentextbookstore
- measurement and significant figures lab millersburg area school district
- surface area and volume of 3 d objects radford university
- chapter 2 introduction to matlab programming elsevier
- experiment 2 measurement and significant figures suny morrisville