What Have We Discussed

1. We use the followng geometrical instruments to construct shapes:

(i)A graduated ruler

(ii) The compasses

(iii) The divider

(iv) Set-squares

(v) The protractor

2. Using the ruler and compasses, the following constructions can be made:

(i) A circle, when the length of its radius is known.

(ii) A line segment, if its length is given.

(iii) A copy of a lines segment.

(iv) A perpendicular to a line through a point

(a) on the lines (b) not on the line

(v) The perpendicular bisector of a line segment of given length.

(vi) An angle of a given measure.

(vii) A copy of an angle.

(viii) The bisector of a given angle.

(ix) Some angles of special measures such as:

(a)90° (b)45° (c)60° (d)30° (e)120° (f)135°