Construct the perpendicular from a point to a line - Loci and constructions - WJEC - GCSE Maths Numeracy (WJEC) Revision

Constructing the perpendicular from a point to a line

To construct a perpendicular line that goes through a given point to a line, you will need a compass and a ruler.

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Drawing the perpendicular from a point to a line
To draw a perpendicular line from the point P to the line, start by setting your compass so that it reaches just beyond the line. Keep your compass this size for the rest of the question.
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Drawing the perpendicular from a point to a line
Draw an arc that cuts the line in two places.
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Drawing the perpendicular from a point to a line
From each intersection point, draw an arc below the line. If they do not meet, go back and extend each arc.
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Drawing the perpendicular from a point to a line
Draw a straight line from P, through the cross you have just drawn.
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Drawing the perpendicular from a point to a line
You can check your answer is accurate by measuring the angle between the two lines. As you have drawn the perpendicular, the two lines should meet at a 90° angle.