Page 30 - ENGINEERING DRAWING

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2.6 Constructing Circle

i. Constructing a circle through 3 given points

CONSTRUCTION

1. A straight line is drawn connecting A to B and B to C.
2. Divide the line into two equal parts for each line AB and BC.
3. Divide the lines into two equal sections for each line AB and BC to intersect at O.
4. By using O as the centre of the circle and radius OA, construct a circle through points
A, B and C as in the diagram.

i. Construct the incircle of a triangle

CONSTRUCTION

1. Draw triangle abc.
2. Construct the bisector of angle abc as shown.
3. Construct the bisector of angle acb as shown.
4. The bisectors meet a point o, the incentre of the triangle
5. Using O as centre, construct the incircle of the triangle abc.