OL Maths

OnlyOptical

How many constructions do we need for OL maths?

skippy1977

21 Constructions for Ordinary Level.

You will have covered 1 to 15 at Junior Cert Level so 16-21 are specific to Leaving Cert Ordinary Level.

From Syllabus
The prescribed constructions are:
1. Bisector of a given angle, using only compass and straight edge.
2. Perpendicular bisector of a segment, using only compass and straight edge.
3. Line perpendicular to a given line l, passing through a given point not on l.
4. Line perpendicular to a given line l, passing through a given point on l.
5. Line parallel to given line, through given point.
6. Division of a segment into 2, 3 equal segments, without measuring it.
7. Division of a segment into any number of equal segments, without measuring it.
8. Line segment of given length on a given ray.
9. Angle of given number of degrees with a given ray as one arm.
10. Triangle, given lengths of three sides.
11. Triangle, given SAS data.
12. Triangle, given ASA data.
13. Right-angled triangle, given the length of the hypotenuse and one other side.
14. Right-angled triangle, given one side and one of the acute angles (several cases).
15. Rectangle, given side lengths.
16. Circumcentre and circumcircle of a given triangle, using only straight-edge and compass.
17. Incentre and incircle of a given triangle, using only straight-edge and compass.
18. Angle of 60, without using a protractor or set square.
19. Tangent to a given circle at a given point on it.
20. Parallelogram, given the length of the sides and the measure of the angles.
21. Centroid of a triangle.

OnlyOptical

Thanks Skippy for the quick reply

pinkbear

Also (I believe) 22. Orthocentre of a triangle.

Am I right?

skippy1977

pinkbear wrote: »

Also (I believe) 22. Orthocentre of a triangle.

Am I right?

No...not for OL...Higher Level must also learn 22 though.