Did You Know……
That the area of triangle is half the area of the respective square of rectangle.
The area of rectangle (red) = 6cm x 3cm = 18 cm2
Using the counting method, the area of (yellow) = 9 cm2 (Ans)
Using the formula, area of (yellow) = 1/2 x 6 cm x 3 cm = 9 cm2 (Ans)
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>>>>
Below are two examples of how the formula is being used to find the area of a triangle.
Example 1
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
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
Paya Lebar Methodist Girls’ School 2022 Prelim Math P2 Q1
Methodist Girls’ School 2022 Prelim Math Q4 Area Triangle
Solution to MGS Prelim Math Q4>>>>>
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Extra Questions For Your Own Practice
Solutions
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