Measurement and Units

Measuring Area and Volume

Measuring Area

Area is a quantity to express part of a surface.

SI unit : m2

Area is needed to determine size of land.

Painters use area to determine the amount of paint to use.

Measuring Area

Regular Figures

L x L L x h ½ x b x h x r2

Measuring Area

Irregular Figures

Estimate area using a square grid made up of many 1cm2

1cm

1cm

Number of ticks = 12

Area = 12cm2 (approx.)

Measuring Area

How to measure irregular figures more accurately

1 x 1cm2 = 1cm2 (approx) 9 x 0.25cm2 = 2.25cm2 (approx)

Measuring Volume

Regular Objects

L x L x L r2 x h (1/3)x r2 x h (1/3)x base area x h

Measuring Volume

Irregular Objects

Estimate volume by using displacement of water

Pour liquid into

measuring cylinder

Volume of liquid = 20cm3

Volume of Object = 20cm3

Conclusion

Area Formulas for regular shaped Tick Estimation for irregular shapes

Volume Formulas for regular object Overflow can for irregular objects