Expressing the Area in Square Units

Expressing the Area in Square Units

Consider a square of side 1 cm. Therefore, its area is 1 sq. cm (1 cm²). Divide one of its sides into 10 equal parts. One such part is equal to 1 mm. We know that 1 cm = 10 mm. That is a square of side 1 cm is made up of 100 small squares with 1 mm square area each. Therefore, the side of this square is 10 mm and the area of this square = side × side =10 mm × 10 mm = 100 sq. mm (100 mm²). Therefore, the area of a square with 1 cm side is 1 cm² = 100 mm².

Similarly, the other conversions can also be done. For example,

i) 1 cm² = 10 mm × 10 mm

             = 100 mm²

ii) 1 m² = 100 cm x 100 cm

             = 10,000 cm²

iii) 1 km² = 1000 m x 1000 m

                 = 10,00,000 m²

Example 15

Fill in the blanks.

i) 2 cm² = _____ mm²

ii) 18 m² = _____ cm²

iii) 5 km² = _____ m²

Solution

 i) 2 cm² = 2 × 100 = 200 mm²

ii) 18 m² = 18 × 10000 = 1,80,000 cm²

iii) 5 km² = 5 × 1000000 = 50,00,000 m²

DO YOU KNOW?

1 acre = 4046.86 m²

1 hectare = 10,000 m²

Try these

Fill in the blanks

i) 7 cm² = 700 mm²

ii) 10 m² = 100000 cm²

iii) 3 km² = 3000000 m²

ICT CORNER

Perimeter and Area

Expected Outcome

Step – 1

Open the Browser by typing the URL Link given below (or) Scan the QR Code. GeoGebra work sheet named “Perimeter and Area” will open. There is a worksheet under the title Counting by squares.

Step – 2

Click on New Problem and find the perimeter and Area of the shape by counting along the squares. Click on the respective check boxes to check your answer.

Browse in the link:

Perimeter and Area: https://ggbm.at/dxv8xvhr or Scan the QR Code.