Solve problems with or without a calculator Level 4

the mid-point and perpendicular bisector of a line segment. the bisector of an angle. the perpendicular from a point to a line segment. the perpendicular from a point on a line segment. Construct triangles to scale using ruler and protractor (SAS, ASA)and using straight edge and compasses (SSS) Why are compasses important when doing constructions? ................
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