I would construct an equilateral triangle, which would give me a 60° angle
(easy to do: just draw a suitable base length, set your compass equal to
that base length, draw arcs above from both ends of the base, connect the ends of the base line to the intersection of the arcs. You have constructed a triangle with 3 equal sides, so the angles are all equal to 60° )
Now bisect that 60° angle, then construct sides of 4.5 cm and 6 cm of the
sides asked for. And there you have it!!
Using a ruler and a pair of compasses only construct
Triangle abc such that ab=4.5cm ac=6cm and bac = 30
3 answers
Construction
1. Draw a line segment AB of length 4.5 cm.
2. Draw a circle with center A and radius 6 cm. This circle intersects AB at a point C.
3. Join AC and BC to form triangle ABC.
4. To construct the 30 degree angle at A, draw a line from A perpendicular to AB and mark the midpoint D of AB.
5. Using the compass, draw an arc centered at D with radius AB.
6. With the same radius, draw another arc centered at A intersecting the first arc at point E.
7. Draw a line from A to E. This forms a 30 degree angle at A.
8. Label the intersection of BC and AE as point F.
9. Triangle ABC is now constructed with sides AB = 4.5 cm, AC = 6 cm, and angle BAC = 30 degrees.
2. Draw a circle with center A and radius 6 cm. This circle intersects AB at a point C.
3. Join AC and BC to form triangle ABC.
4. To construct the 30 degree angle at A, draw a line from A perpendicular to AB and mark the midpoint D of AB.
5. Using the compass, draw an arc centered at D with radius AB.
6. With the same radius, draw another arc centered at A intersecting the first arc at point E.
7. Draw a line from A to E. This forms a 30 degree angle at A.
8. Label the intersection of BC and AE as point F.
9. Triangle ABC is now constructed with sides AB = 4.5 cm, AC = 6 cm, and angle BAC = 30 degrees.
1 answer