Constructing a triangle from three sides
Constructing a triangle from three sides.
- Use a sharp pencil, ruler and compasses or protractor as specified.
- Keep the arcs and guide marks that show how the construction was made.
- Check the required lengths and angles without erasing the construction.
Example 1
Construct triangle ABC with AB = 4 cm, AC = 3 cm and BC = 5 cm. Keep your construction marks.
Draw AB = 4 cm. Draw an arc of radius 3 cm centred at A and one of radius 5 cm centred at B. Their intersection is C. Join AC and BC.
Example 2
Construct triangle ABC with AB = 5 cm, AC = 3 cm and BC = 6 cm. Keep your construction marks.
Draw AB = 5 cm. Draw an arc of radius 3 cm centred at A and one of radius 6 cm centred at B. Their intersection is C. Join AC and BC.
Your turn
Construct triangle ABC with AB = 6 cm, AC = 3 cm and BC = 7 cm. Keep your construction marks.
Check answer
Draw AB = 6 cm. Draw an arc of radius 3 cm centred at A and one of radius 7 cm centred at B. Their intersection is C. Join AC and BC.
Construct triangle ABC with AB = 7 cm, AC = 3 cm and BC = 8 cm. Keep your construction marks.
Check answer
Draw AB = 7 cm. Draw an arc of radius 3 cm centred at A and one of radius 8 cm centred at B. Their intersection is C. Join AC and BC.
Construct triangle ABC with AB = 8 cm, AC = 3 cm and BC = 9 cm. Keep your construction marks.
Check answer
Draw AB = 8 cm. Draw an arc of radius 3 cm centred at A and one of radius 9 cm centred at B. Their intersection is C. Join AC and BC.
Construct triangle ABC with AB = 9 cm, AC = 3 cm and BC = 10 cm. Keep your construction marks.
Check answer
Draw AB = 9 cm. Draw an arc of radius 3 cm centred at A and one of radius 10 cm centred at B. Their intersection is C. Join AC and BC.
Construct triangle ABC with AB = 10 cm, AC = 3 cm and BC = 11 cm. Keep your construction marks.
Check answer
Draw AB = 10 cm. Draw an arc of radius 3 cm centred at A and one of radius 11 cm centred at B. Their intersection is C. Join AC and BC.
Construct triangle ABC with AB = 6 cm, AC = 3 cm and BC = 7 cm. Keep your construction marks.
AnswerDraw AB = 6 cm. Draw an arc of radius 3 cm centred at A and one of radius 7 cm centred at B. Their intersection is C. Join AC and BC.
Construct triangle ABC with AB = 7 cm, AC = 3 cm and BC = 8 cm. Keep your construction marks.
AnswerDraw AB = 7 cm. Draw an arc of radius 3 cm centred at A and one of radius 8 cm centred at B. Their intersection is C. Join AC and BC.
Construct triangle ABC with AB = 8 cm, AC = 3 cm and BC = 9 cm. Keep your construction marks.
AnswerDraw AB = 8 cm. Draw an arc of radius 3 cm centred at A and one of radius 9 cm centred at B. Their intersection is C. Join AC and BC.
Construct triangle ABC with AB = 9 cm, AC = 3 cm and BC = 10 cm. Keep your construction marks.
AnswerDraw AB = 9 cm. Draw an arc of radius 3 cm centred at A and one of radius 10 cm centred at B. Their intersection is C. Join AC and BC.
Construct triangle ABC with AB = 10 cm, AC = 3 cm and BC = 11 cm. Keep your construction marks.
AnswerDraw AB = 10 cm. Draw an arc of radius 3 cm centred at A and one of radius 11 cm centred at B. Their intersection is C. Join AC and BC.