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Constructions Tutorials

Welcome to the construction zone!
One of the tricky elements of geometry is the “construction” – a task whereby students must use their tools to construct up to 22 geometric shapes and figures using mathematical principles and tools. These tools used are the following:

 – Usual essentials: Pencil, Rubber, Ruler, Sharpener etc.
 – Compass: Used for drawing circles and arcs.
 – Protractor: Used for measuring and drawing angles.
 – Set Square / “Triangle” : Typically 45-degree and 60-degree triangles used for drawing perpendicular lines.

Here’s how to complete all 22 of the construction tasks, step by step. Swipe the slider along the bottom to follow along!


Basic Constructions

If you’re starting from scratch or having trouble with more advanced constructions, this is the place to start.

Construction 1

Using only a compass and straight edge, bisect the angle shown:

Construction 2

Using only a compass and a straightedge, construct a perpendicular bisector on the line shown:

Construction 3

Construct a line perpendicular to the current line, passing through the point A.

Construction 4

Construct a line perpendicular to the current line, passing through the point A.

Construction 5

Construct a line perpendicular to the current line, passing through the point A.

Line Segment Constructions​

Construction 6 & 7

Construct a line perpendicular to the current line, passing through the point A.

Construction 8

Construct a line segment of 6cm on the given ray |AB|:

Angle Constructions​

Construction 9

Construct an angle of 60° with the given ray below:

Construction 18

Construct an angle of 60° without using a protractor or set square, but a compass and a straight edge only. Show all work clearly:

Triangle Constructions​

Construction 10

Construct a triangle with sides 4cm, 5cm, and 6cm:

Construction 11

Construct a Right Angle Triangle ABC where |AB| = 6cm, |∠BAC| = 70° and |AC| = 4cm. Show your construction lines clearly:

Construction 12

Construct a Right Angle Triangle ABC where |AB| = 6cm, |∠BAC| = 70° and |∠ABC| = 30°. Show your construction lines clearly:

Construction 13

Construct a Right Angle Triangle ABC where the hypotenuse |BC| = 10cm, and |AB| = 6cm. Show your construction lines clearly:

Construction 14

Construct a Right Angle Triangle ABC where |AB| = 5cm, and |∠ACB| = 60°. Show your construction lines clearly:

Rectangle and Parallelogram Constructions

Construction 15

Construct a Rectangle ABCD where |AB| = 12cm and |AC| = 4cm. Show your construction lines clearly:

Construction 20

Construct a Parallelogram ABCD where |AB| = 8cm, |AC| = 5cm, and |∠BAC| = 60°. Show your construction lines clearly:

Circle Constructions​

Construction 16

Construct the circumcentre and circumcircle of the Triangle XYZ shown below, using only a compass and a straight edge. Label the circumcentre C. Show your construction lines clearly:

Construction 17

Construct the incentre and incircle of the Triangle XYZ shown below, using only a compass and a straight edge. Label the incircle. Show your construction lines clearly:

Construction 19

Construct the line tangent to the circle with centre C at point T using only a Compass and Straight Edge. Show all workings clearly:

Construction 21

Construct the line tangent to the circle with centre C at point T using only a Compass and Straight Edge. Show all workings clearly:

Construction 22

Construct the orthocentre of the Triangle XYZ shown below, using only a compass and a straight edge. Label the orthocentre. Show your construction lines clearly: