Page 107 - Mathematics_Std_4

3. One side of a square garden is 21 metres long. Find the
area of the garden.

4. The floor of a square classroom has one side of length
9 metres. Find the area of the floor.
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5. The length of one side of a square farm is 170 metres.

Find the area of the farm.
6. A window with a square shape has a length of

140 centimetres. Find the surface area of the window.

Area of a triangle
The area of a triangle is the surface region of the triangle.

Activity 2 Determining the area of a triangle

Steps

1. Draw a square LMNO on graph paper.

2. Draw a line segment to join the points L and N to form two
triangles LMN and LON.

3. Count the complete small squares and half small squares

in the triangle LON.
4. How many complete small squares do you get?

5. How many half-small squares do you get? (Remember that

two half squares make one complete square).
6. What is the total number of complete squares in the triangle

LON?

7. Is there any relationship between the triangles LON and
LMN?

8. What is the relationship between the triangles LON, LMN
and the area of the square LMNO?

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MATHEMATICS STD 4 PB 2024.indd 100
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MATHEMATICS STD 4 PB 2024.indd 100 06/11/2024 17:17:24