Find out about Triangles

Adapted from : Burns, M. (1994) The Greedy Triangle. USA

What are the different parts of a triangle?

BASE

HEI GHT

What are the different parts of a triangle?

Finding the base and height of a triangle

The different types of triangles

Right Angled TrianglesAcute Angled TrianglesObtuse Angled Triangles

Right angle

SimilaritiesAll of them have 3 sides and 3 angles

Differences

Right Angled Triangles - One has a right angle and two angles less than 90°

Acute Angled Triangles – One has three angles less than 90 °

Obtuse Angled Triangles – One has an angle greater than 90 ° and two angles less than 90 °

Let’s identify the base and height of a right angled triangle

Let’s identify the base and height of n acute angled triangle

Let’s identify the base and height of an obtuse angled triangle

Think-Pair-Share

1. Draw a straight line on your Mini Whiteboard and label it base.

base

Think-Pair-Share2. Mark a point on top and within the length of the line.

.

base

Think-Pair-Share

3. From the dot, extend a line to join to each side at end of the first line.

.

Think-Pair-Share

4. Pass it to your partner and get him/her to identify the height of the given triangle.

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Think-Pair-Share

Switch the role with your partner and repeat step1 to 6

Level 2…

1. Draw another straight line on the Mini Whiteboard and label it base.

base

Level 2…2. Mark another point on top but not within

(outside) the length of the line.

.

base

Level 2…3. From the dot, extend a line to join to each side at end of the first line.

.

base

Level 2…3. From the dot, extend a line to join to each side at end of the first line.

.

base

Level 2…4. Pass the triangle you have drawn to your partner and he/she will repeat the

step 5 and 6 as in the previous triangle.

base