If one shape can fit exactly on top of another using rotation, reflection or translation, then the shapes are congruent.

Constructing a triangle given two angles and the side length between them

Maths

The constructions covered in the prior unit are built on in this unit. In this unit, pupils construct triangles and construct diagrams following specific restrictions.

Loci and construction

a rubber to rub out all construction lines

What equipment should you use to make an accurate construction of this triangle?

The diagram shows part of a protractor measuring an angle. What is the size of the angle?

Laura is using GeoGebra to accurately draw a triangle with ∠BAC = 125° and ∠ABC = 32° and side AB = 5 units. Which tool should Laura use to plot point C?

Use a protractor to measure 38° from A and mark a faint point.

Repeat the last step with point B and an angle of 43°.

Draw a ray line to show direction of side AC.

Draw a second ray line to show direction of side BC.

Label point C at the point where the two rays meet.

Match each step to the correct instruction needed to construct triangle ABC.

The diagram shows a protractor measuring an angle. What is the size of the angle?

Jacob is using GeoGebra to accurately draw a triangle with side lengths 8 units, 9 units and an angle of size 67° between them. Which tool should Jacob use to construct a ray line?

A pair of compasses is used to draw an arc. The value of $$x$$ is {{ }}.

Laura draws a ray line and a circle with radius 10 units then marks their intersection with point C. Which line segment has a length of 10 units?

Use a protractor to measure 52° at A and mark a faint point.

Draw a ray line through A to show direction of AB.

Set compasses to width of 9 cm and mark an arc on the ray.

Label point where arc meets the ray as B.

This lesson will soon be taken down.

Constructing a triangle given two angles and the side length between them

Lesson outcome