Types Of Triangles (KS2) Explained For Parents

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We understand teaching KS2 maths at home is challenging, especially when the techniques to teach maths change so often: how we learnt about triangles may not be how your children are taught them!

This blog will cover types of triangles, what your child needs to know about them at different ages, the key equations children are expected to know and some suggestions for teaching. Maths can be fun and exciting, so we are here to outline how to maximise the fun potential for learning geometry.

Each child will have their own preferences for learning, this is a guide to help inspire and encourage children to be enthusiastic about the different types of triangle.

What Are The Different Types Of Triangle?

A triangle is a 3 sided, 2D shape and learning all about them forms part of the primary school curriculum. You can use these to introduce your child to triangles.

Equilateral triangle:

All of the sides have equal sides. All of the angles are equal and always add up to 60º.

Right angled triangle:

A right angled triangle has one 90º angle. The longest side of this one is known as the hypotenuse. The side opposite the right angle is known as the opposite.

Isosceles triangle:

This triangle has two equal sides and two equal angles.

Scalene triangle:

A scalene has sides which are all of a different length. All of the interior angles are different in this one.

Which Equations Does Your Child Need To Know?

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The sum of the internal angles of a triangle = 180º.

When you add the three internal angles together they should add up to 180º.

Year 5 pupils may be introduced to this and Year 6 pupils will be expected to find a missing interior angle using this knowledge.

The emphasis for the older years is to put their knowledge of the right angles, equal angles and interior angles into practice through solving problems.

The area of a triangle:

To work out the area, times the length of the base by the length of the height then divide the answer by 2. It can be represented like this:

base x height



It can also be represented like this:

1/2 x base x height

Year 5 pupils may be introduced to these equations and Year 6 pupils are expected to use them to work out the area of a triangle. Year 6 pupils will also be asked to work out a missing interior angle of a triangle.

How Can You Teach Your Children Triangles For KS2?

At-home learning can often be a challenge; we have tried to make the search for activities easier. With a geometry topic like triangles, you can utilise your surroundings to get children really excited about maths in the real world. Here are some suggestions, increasing in difficulty:

Treasure hunt: walk around the house together and see how many triangles you can spot- you can be as creative as you like and ask the children to identify which type it is. If you have time, cutting out triangles and hiding them around the house is a great way to add to this activity.

Rapidough: if you have any plasticine or another malleable craft substance then you can play this game. You can let the children play with each other or join in yourself. Player 1 starts by moulding the shape and player two has to guess which type of triangle it is. If they guess correctly, they get to take some plasticine from the player one. Keep going until one player has all the plasticine.

Questions with an active twist: You can say different types of triangles to the child, for example an equilateral, the child has to try to make the shape using their body.

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Singing SATs questions: if you want to ease your children into answering SATs questions, try singing the questions (as silly as you like!) to each other before the child answers them. Teaching maths at home can sometimes be frustrating for everyone and laughter can be the best medicine.

How Are Triangles Usually Taught To KS2 Pupils?

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Year 3: Right-angles are usually introduced to pupils. They are encouraged to identify which triangles have right angles.

Year 4: They will learn about more advanced properties of shapes, including obtuse and acute angles. They will answer questions about the different properties and identify different types of triangle with those properties.

Year 5: Consolidation of the different types of triangles learnt in Year 4. For pupils who find this straightforward, they may be introduced to some simple equations, for example finding a missing interior angle.

Year 6: Pupils complete equations to find a missing interior angle and are taught the equation to find the area of a triangle. They will be taught to do this with all different types of triangle.



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