Practical Mathematics : Measuring area of Jurong Island.

Use Google Planimeter at http://www.acme.com/planimeter/ Result : Area of Jurong Island is estimated as 24.19 km2.

Lesson Idea : Area of Plane Linear Figures using the Shoe Lace method (Coordinates of vertices)

Practical Mathematics : Measuring area of Dunman Secondary School Compound

Use Google Planimeter at http://www.acme.com/planimeter/ Result : Area of Jurong Island is estimated as 0.03124 km2 (3.124 hectares/31240 m2)

Lesson Idea : Area of Plane Linear Figures using the Shoe Lace method (Coordinates of vertices)

Use Geogebra to measure the same area of Dunman Secondary School Compound.

Copy and save the image of the map.

Start Geogebra and insert this map as an image in Geogebra file.

Adjust the size of the image relative to the units on the x axis that 1 unit in Geogebra’s axis represents 50 m on the map

Create new points over the map image’s marked corner points (vertices)

Use the polygon tool to enclose all the vertices. Use Area tool to find enclosed area.

Obtain the area of Dunman Secondary School Compound in terms of square units on the graph. Ans :12.582 units 2

Convert the square units to m2 ( 1 unit2 => 502 m2 => 2500 m2)

Area of Dunman Secondary School Compound found using Geogebra measurements on map image Ans : 31454 m2

See image on next page :

The Geogebra applet is embedded at this site : https://sites.google.com/a/moe.edu.sg/dmnteachgeogebra/geogebra-lessons-pages/mapmeasure