Starter quiz
- Which of these statements describe the properties of all triangles?
- 3 straight sides ✓
- 1 right angle
- 3 vertices ✓
- 2 sides the same length
- obtuse angles
-
True or false. The images are all triangles.- True
- False ✓
Match the different triangles to their properties.- A⇔no equal sides and no equal angles ✓
- C⇔two equal sides and two equal angles ✓
- B⇔three equal sides and three equal angles ✓
- How many equal sides and equal angles does an isosceles triangle have? ______
- 0
- 1
- 2 ✓
- 3
-
- A triangle with 3 equal sides and 3 equal angles is called an __________ triangle.
- equal
- isosceles
- equilateral ✓
- scalene
-
- How many equal sides and equal angles does a scalene triangle have?
- 0 ✓
- 1
- 2
- 3
-
Exit quiz
- Which of these is true for all right-angled triangles?
- They have 3 equal angles.
- They have 2 equal angles.
- They have 1 right-angle. ✓
- They have 1 obtuse angle.
-
These triangles have been sorted. What type of triangles are in this set?- scalene
- isosceles ✓
- equilateral
- right-angled
-
These triangles have been sorted. Which triangle has been incorrectly sorted?- a ✓
- b
- c
-
- True or false. Right-angled triangles can be scalene or isosceles.
- True ✓
- False
Jacob has made these triangles. Match the triangle to the correct description.- a⇔a right-angled isosceles triangle ✓
- b⇔an equilateral triangle ✓
- c⇔a right-angled scalene triangle ✓
This shape is a right-angled ______ triangle.- 'scalene' ✓
Worksheet
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Presentation
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Video
Lesson Details
Key learning points
- There are three types of triangle - equilateral, isosceles and scalene.
- Some triangles can also be described as right-angled triangles if one of the angles is equal to 90°
- Right-angled triangles can be classified as scalene or isosceles.
Common misconception
Children might find it difficult to create triangles with equal angles.
Allow time to play and explore constructing triangles using items such as lolly sticks and matchsticks. Develop children's understanding of angles in a triangle using angle strips to check whether the angles are equal or not.
Keywords
Right-angled triangle - A right-angled triangle has one 90° angle. Right-angled triangles can be classified as isosceles or scalene.
Equilateral triangle - Equilateral triangles have 3 equal sides and 3 equal angles.
Isosceles triangle - Isosceles triangles have 2 equal sides and 2 equal angles.
Scalene triangle - Scalene triangles have no equal sides and no equal angles.
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