straightedge
a ruler with no markings on it
compass
a geometric tool used to draw circles and parts of circles called arcs
angle bisector
a ray that divides an angle into two congruent coplanar anfles
construction
you use a straightedge and a compass to draw a geometric figure
perpendicular lines
two lines that intersect to form right angles
perpendicular bisector
a segment is a line, segment, or ray that is perpendicular to the segment at its midpoint, thereby bisecting the segment into two congruent segments