Primary Math

area-of-triangle

All About Area Of Triangles

Did You Know……

That the area of triangle is half the area of the respective square of rectangle.

 

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The area of rectangle (red) = 6cm x 3cm = 18 cm2

Using the counting method, the area of (yellow) = 9 cm2 (Ans)

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Using the formula, area of (yellow) = 1/2  x 6 cm x 3 cm = 9 cm2 (Ans)

yellow-area-grid-triangle

In Primary 3, the students are first taught how to find the area and perimeter of a rectangle and square. They attain more mastery in the topic in Primary 4.

By Primary 5, students will be exposed to the next topic, Area Of Triangles. The students must first identify the base of triangle and the perpendicular height, corresponding to the base.

Some of the questions can be rather challenging as it not only tests the students understanding, it also tests the students visualization skills especially when 2 or more shapes overlapped one another.

Let us practice some questions>>>>

rectangle-area

 

Below are two examples of how the formula is being used to find the area of a triangle.

Example 1

triangle

Find the area of a right angle triangle with a base of 6cm and a height of 9cm.

Solution

Area of triangle = 1/2 x B x H

= 1/2 x 6cm x 9cm

= 1/2 x 54 cm2

= 27cm2

Example 2

triangle

Find the area of the triangle shown below.

Solution

Area of triangle = 1/2 x B x H

= 1/2 x 8cm x 3cm

= 12 cm2

 

Using the counting method to find the areas of Triangle B and Triangle C and their related rectangles OPQR and MNOP.
What do you notice about the area of triangle and the area of the related rectangles?

Yes! the area of triangle is half the area of rectangle or square

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Paya Lebar Methodist Girls’ School 2022 Prelim Math P2 Q1
area-of-triangle-formula

Solution to PLMGS P2 Q1 >>>>>

Methodist Girls’ School 2022 Prelim Math Q4 Area Triangle
angles-triangle-area

Solution to MGS Prelim Math Q4>>>>>         

Raffles Girls’ Primary School 2021 Prelim P2 Q16

area-question-triangle

Solution to RGPS Prelim Math Q16>>>>>   

Extra Questions For Your Own Practice
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triangle

triangle

triangle

triangle

triangletriangle

 

Solutions
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solution

solution

solution

Interested in articles like this? Check this one out!! >>>>>
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