Presentation on theme: "Topic Area and volumes of plane figures"— Presentation transcript:
1 TopicArea and volumes of plane figuresArea and volumes of solid figures
2 Learning outcomesStudents will be able to understand the method of finding areas of figures like:TrapeziumRegular pentagonCubecylinder
3 They will be able to find the volume and surface area of : Cuboids/cubeCylinderApply the concepts in daily life mathematical problems.
4 Previous knowledge Square: side x side Rectangle : length x breadth Triangle : ½ base x height or altitudeCircle ∏r2 where r is the radius
5 Area of some special figures TrapeziumA trapezium has one pair of opposite side parallelABAB is parallel to BDhCDArea=1/2h(sum of parallel sides)
6 Area of regular hexagon We can find of hexagon in different ways
7 method1This hexagon can be divided into two trapezium
8 Method 2The hexagon is divided into two triangles andone rectangle
9 Surface area of a cylinder Let us roll a rectangular sheet of paper2 ∏rh
10 We see that the length of the sheet will be the circumference of the circle And the height of the cylinder is the breadth of the sheet.Area of the sheet = l x b which is same as :Area of the cylinder 2 ∏r x h
11 Volume : it s the space occupied by an object: Volume of a cuboid= lx b x hVolume of a cylinder = ∏r2 h
12 The unit of measurement of area is square units e g cm2 m2 etc The unit of measurement of volume is cubic units e g cm3 m3 or if we are measuring liquids it will be ml litres.
13 What is the difference between capacity and volume? What is the relation between the units cm3 and mlA rectangular sheet 11cm x 4 cm is folded to make a cylinder of height 4cm .Find the volume of the cylinder so formed.
14 Assignment Find the area of the given figures 4cmA regular hexagon having side 5cm11cm