G:\Panitia\Presentation Earth As A Sphere

MATHEMATICS FORM 5

NORTH POLE

SOUTH POLE

EASTWEST

LONGITUDELATITUDE

MALAYSIA●

Great circle is any circle that passes through the north and the south poles or with the center as the centre of the earth.

GREAT CIRCLE

●O

N

S

One-half of a great circle joining the North and the South Poles is called a meridian.

SS

N

● OO

Longitude of a meridian is determined by the angle between its plane and the plane for Greenwich Meridian (east or west).

Greenwich Meridian 0 o

LONGITUDE

Example :

G is stated on the Greenwich Meridian .

L is 80o to the right of G.

So the longitude of L is 80o E.

K is 60o to the left of G.

So the longitude of K is 60o W.

K and M is a diameter of a circle centred C.

KCM = 180o .

So Longitude M is 120o E

N

EXERCISE 1: State the longitude of (a) dan (b)

(a) 100o E / 100o W

(b) 80o E/ 180o W

(a)

(b)

N

E

Where is our country, Malaysia stated ?

The Great Circle which the plane are perpendicular to the poles is known as the equator

Marked as 0o

North directionN

S

0o

South direction

•The circle with plane which are parallel to the equator plane is known as parallel of latitude

LATITUDE

Latitude

Get further information about latitude and longitude at the following address:

http://www-spof.gsfc.nasa.gov/stargaze/Slatlong.htm

Latitude Of a Point

Latitude is an angle at the centre of the earth that subtended by a meridian beginning from the equator to the parallel of latitude which is either to the North or to the South of the equator.

Latitude A is 50o N●A

Latitude B is 10o S ●B

NORTH

SOUTH

EQUATOR

N NN

N

S

SS S

Look at the angle made by equator plane and parallel latitude 60o N

The angle between the equator plane and the north plane is 90o

Example :

Based on the diagram, O is the centre of the earth

State the latitude of point

(a) W (b) X (c) Y

Solution:

(a) W is 72o to the north equator.

So the latitude for W is 72o N.

(b) X is 65o to the south equator

So the latitude for X is 65o S.

(c) Y is located at the same parallel latitude with W. Thus, latitude for Y is 72o U.

Exercise 2 : State the latitude of the following

point :

1. Latitude Q is 3. Latitude L is

Q

N

2. Latitude P is

68 o N 55 o N 68 o N 68 o S55o S 55o N

Location Of A Place

Location of a place at the surface of the earth can be determine by its latitude and longitude

For example, based on the above figure Paris is located at point P

Location of Paris is written as (48o 50’ N,20o 20’ E)

What is the location of Q ?

LONGITUDE = 100O E

LATITUDE = 5O N

MALAYSIA ( 5O N, 100O E )

E1 E 2

E1 E2