How do I find the midpoint of a line segment?

By Lee Mansfield on the 11th of June, 2012

1 Answer

  • 0

    Suppose you have a line segment AB and you want to find the midpoint of it.
    Draw a circle around A and a circle of the same radius around B (make sure these circles have a radius of more than half the length of AB)
    These 2 circles will have 2 intersections (labelled C and D below)
    Draw a line from C to D.
    The line CD will cross AB at its midpoint.

    Refine By Lee Mansfield on the 14th of June, 2012

Suggested reading…

Find the midpoint of a line segment

We sometimes call a line a line segment instead. We do this because a line is supposed to go on forever in both directions, so when it doesn’t, we say we’re just looking at one ‘segment’ of the line.

The midpoint of a line segment is the point right exactly bang in the middle of it. You can find it by measuring it with a ruler, but actually there’s a more accurate way of doing it, using a compass.

Using a compass

We draw a semi circle, with the 'centre' at one end of the line segment, and the radius asthe length of the line. We do the same at the other end of the line. We then draw a line where the two semi circles meet.

Related Questions