2. DEFINITION OF MENSURATION Topic dealing with the use of formulae to calculate Perimeters, Areas and Volumes of plain shapes and solid ones (prisms).
3. PERIMETER AND AREA PERIMETER THE PERIMETER IS THE DISTANCE AROUND THE BOUNDARY OF A PLANE CLOSED FIGURE. AREA AREA CAN BE DEFINED AS THE SPACE COVERER BY THE SURFACE OF A FIGURE.
4. L L L PERIMETER THERE ARE DIFFERENT FORMULAES FOR FINDING THE PERIMETER OF A PLANE FIGURE: SQUARE: 4 X s RECTANGLE: 2 X (l + b) CIRCLE:2 X 3.14 X r
5. AREA OF 2D FIGURES THERE ARE DIFFERENT FORMULAES FOR FINDING THE AREA OF A PLANE FIGURE: RECTANGLE: l X b SQUARE: s2 TRIANGLE: ½ X b X h PARALLELOGRAM: b X h CIRCLE: 3.14 X r2 TRAPEZIUM : ½ X h(a+b) (WHERE a IS FIRST PARALLEL LINE , b IS SECOND PARALLEL LINE AND h IS HEIGHT)
6. h b l AREA OF 3D FIGURES THERE ARE DIFFERENT FORMULAES FOR FINDING THE AREA OF A PLANE FIGURE: CUBE:6l2 CUBOID:2 X h X (l + b) CYLINDER: 2 X 3.14 X r X (r +h)
7. 1000m BASIC PROBLEMS Q1. SHYAM HAS A SQUARE PLOT OF SIDE 1000m. FIND THE AREA. ANS1. SIDE OF SQUARE PLOT = 1000M THEREFORE, AREA = 1000m2 = 10,00,000m2
8. 300km 200km 120km BASIC PROBLEMS Q2. SHRI OWNS A TRAPEZIUM PLOT OF 1ST PARALLEL LINE = 300km , 2ND PARALLEL LINE = 200km AND THE DISTANCE BETWEEN THEM = 120km. FIND THE AREA OF THE PLOT. ANS2. 1ST PARALLEL LINE = 300km.THE 2ND PARALLEL LINE =200km AND HEIGHT = 120km. AREA = ½ x 120km (300km + 200km) . THEREFORE, AREA =½ X 120km X 500km = 30,000km2
9. 5m 500M 400M 5m BASIC PROBLEMS Q3 RAM OWNS A RECTANGULAR PARK OF l = 500m AND b = 400m. HE CONSTRUCTS A FOOTPATH OF 5m ALONG ITS ALL SIDES. FIND THE AREA OF THE FOOTPATH. ANS3 LENGTH OF RECTANGLE = 500m BREADTH OF RECTANGLE = 400m THE AREA OF RECTANGLE = 500m X 400m =2,00,000m2 LENGTH OF OUTER RECTANGLE = 510m BREADTH OF OUTER RECTANGLE = 410m AREA OF OUTER RECTANGLE = 510m X 410m = 2,09,100m2 AREA OF FOOTPATH = 2,09,100m2 –2,00,000m2 = 9100m2
