GB-37-03-001 · Perpendicular-bisector construction
On plain paper, draw a horizontal line segment AB of length 6.8 cm.
(a) Using ruler and compasses, construct the perpendicular bisector of AB. Leave your construction arcs visible.
(b) Point P lies on this bisector and PA = 10.4 cm. Write down PB.
Part (a)
Constructions: Perpendicular Bisector
Supplementary GCSE method — not covered in this booklet
Method
1) Open compasses to more than half AB and draw arcs from A and B above and below
2) Join intersections with a straight line; points on bisector are equidistant from A and B
Worked Example (GB-37-03-001 · Part (a))
Using ruler and compasses, construct the perpendicular bisector of AB. Leave your construction arcs visible.
1)
Equal-radius intersecting arcs from both endpoints; radius greater than half AB.
2)
Straight line through the arc intersections, perpendicular at the midpoint.
Ans =
Equal-radius arcs from A and B intersect above and below AB; join their intersections.
Part (b)
Constructions: Perpendicular Bisector
Supplementary GCSE method — not covered in this booklet
Method
1) Open compasses to more than half AB and draw arcs from A and B above and below
2) Join intersections with a straight line; points on bisector are equidistant from A and B
Worked Example (GB-37-03-001 · Part (b))
Point P lies on this bisector and PA = 10.4 cm. Write down PB.
1)
10.4 cm
Ans =
10.4 cm