Longitude and Latitude SS3 Mathematics Lesson Note

Instructional Objectives:  At the end of the lesson, students should be able to: 

1. Distinguish between great circles and small circles 
2. Define longitude and latitude 
3. Sketch the position of a point. 
4. Find its angular differences 

Instructional Resource: Model of a global Earth, Oranges 

Presentation: 

Step 1:  Identification of Prior Ideas: 

Mode: The whole class 

Teachers’ activities:  The teacher asks the students to find the circumference of a circle whose radius is 7 cm. Students’ Activities: Answer 

  The teacher explains that when an orange is cut cross-sectional, the top circles are known as small circles. The radius of a small circle is less than the radius of the sphere, while the largest possible circle is known as the Great circle. 

The radius of a great circle of a sphere is equal to the radius of the sphere. Examples of small circles are circles of latitudes except the equator while great circles are circles of longitude. 

Step 2: Exploration:  

Mode: The whole class 

Teachers’ activities: The teacher uses the instructional resources to explain longitude and latitude. 

Longitude: Is a straight line or imaginary line that passes through the centre of the Earth joining the North and South poles. 

   The lines of longitude are also called Meridians; they vary from 1800E to 1800W. 

Students’ Activities: The students were meant to sketch the spheres showing the longitude, equator, polar axis & meridians.  

GREENWITCH MERIDIAN:  Is used as a standard foam in which the positions of other meridians are measured in degree East or West. 

 Step 3: Discussion 

Mode:  The whole class 

Teachers’ activities: The teacher uses the instructional resources to explain latitude. Latitude: Latitude is a circle that is drawn on the earth’s surface having its centre on the axis of the earth (polar axis). The circles of the latitude are PARALLEL to each other; it is known as parallels of latitude. It is measured in degrees NORTH OR SOUTH of the equator, latitudes vary from 900N to 900S. 

Equator is the line of latitude which has the same centre as that of the earth. The latitude of an Equator is 00 

Students’ Activities: The students were meant to sketch the spheres showing the parallel of latitude, equator, polar axis & meridians.  

Step 4:   Application Mode: The whole class Teachers’ Activities. 

The teacher leads the students to determine the position, location of the plane and angles between two places on the Earth’s surface. 

The position of a place is located, by finding the point of intersection of the longitude and latitude of such a place. To do that first, sketch a sphere locating the meridian, equator, longitude and latitudes to locate a point. 

i.e. for any point (lat. N or S, long E or W) Examples: locate the following point. 

A(500N, 1000E) ,    B(500N, 600E),    C(500N, 400W),    D(500N, 700W),     E(700S, 800W),    F(700S, 400W) ,      G(700S, 700E) ,    H(700S, 1000E) W 700 S  

  Step 5: Evaluation:  

Mode: The whole class 

Teachers’ Activities: The teacher asks the following 

1. Define Great circle & small circle 
2. Define latitude & longitude 
3. Sketch the following  positions on the earth’s surface   C(00,  300W),       D(00, 450E),    E(650,  00) ,   F(650S  400E)  

 Assignment: find the radius of Earth’s surface and the radius of parallel or lines of latitude. 

Reference: 

• New General Mathematics for SS3 
• New Concept Mathematics for SS3