Drawing Instruments and Material III

Basic Technology J.S.S 1 Second Term

WEEK 5&6

Drawing Instruments and Material III

Performance Objectives

Students should be able to:

1. Construct shapes e.g. Circles, Triangles, Rectangles with drawing instruments and materials

Content

Geometrical constructions should be drawn with a sharp, hard (2H) pencil. A pencil eraser, a ruler marked in centimetres (often used as a straight edge), a pair of compasses, two set squares (90°, 60°, 30° and 90°, 45°, 45°) and a protractor with a radius of at least 5cm make up the basic set of geometrical instruments.

Using Compasses to Draw a Circle

Suppose we are given an interval AB and a point O. In geometry, we always include the endpoints in an interval.

Open your compasses…