A Trapezium and its properties

Learning objectives

 * 1) A quadrangle with only two opposite sides parallel is called a trapezium, or trapezoid.
 * 2) The parallel sides are called the bases of the trapezium and the other two sides are called the legs or the lateral sides.
 * 3) If the legs are equal in length, then this is an isosceles trapezium.
 * 4) The distance between the bases is called height of trapezium.

Activity No # 1. Properties of a trapezium.
Laptop, geogebra file, projector and a pointer.
 * Estimated Time :40 minutes.
 * Materials/ Resources needed:
 * Prerequisites/Instructions, if any
 * 1) Knowledge about parallel lines, angles and diagnols.
 * Multimedia resources: Laptop.
 * Website interactives/ links/ / Geogebra Applets: This file has been taken from www.geogebratube.org

Are the students able to apply the theorems of parallel lines - transversal to prove the properties.
 * Process:
 * 1) Show the geogebra file and explain its properties by asking the questions listed below.
 * Developmental Questions:
 * 1) What is a trapezium ?
 * 2) How many sides does it have ?
 * 3) What can be said about the pair of sides ?
 * 4) Identify the diagnols. Are they equal ?
 * 5) What would be the sum of 4 angles of the trapezium ? Why so ?
 * 6) What would be the sum of its two allied angles ?
 * 7) Are the two pairs of sides of a trapezium equal ?
 * Evaluation:
 * 1) Why are allied angles of the trapezium supplementary ?
 * 2) Are the diagnols equal ?
 * 3) Is trapezium a parallelogram ?
 * Question Corner:
 * 1) List the properties of a trapezium.
 * 2) What properties of other quadrilaterals does it share. Compare with other quadrilaterals.