Mensuration
- In the figure 7.12, a cylindrical wrapper of flat tablets is shown. The radius of a tablet is 7 mm and its thickness is 5 mm. Radius of a tablet, r = 7 mm Thickness of a tablet, h = 5 mm Radius of cylindrical wrapper, R = 14/2 = 7 mm Height of wrapper (H) = 10 cm =... 1
- In figure 7.11, a toy made from a hemisphere, a cylinder and a cone is shown. Find the total area of the toy Radius of the sphere = Radius of the cylinder = Radius of cone = r = 3 cm Height of the cone, h = 4 cm Height of the cylinder, H = 40 cm Let... 1
- A cylinder and a cone have equal bases. The height of the cylinder is 3 cm and the area of its base is 100 cm2 . Height of the cylinder, h = 3 cm Let the radius of the cylinder be r cm and the height of the cone be H cm. Area of the base of cylinder = 1... 1
- Observe the measures of pots in figure 7.8 and 7.9. How many jugs of water can the cylindrical pot hold ? Given: For the conical water jug, radius (r) = 3.5 cm, height (h) = 10 cm For the cylindrical water pot, radius (R) = 7 cm, height (H) = 10... 2
- The dimensions of a cuboid are 44 cm, 21 cm, 12 cm. It is melted and a cone of height 24 cm is made. Find the radius of its base Radius is 21 cm 1
- Find the surface area of a sphere of radius 7 cm. Answer is 616 sq. cm 1
- Find the total surface area of a cylinder if the radius of its base is 5 cm and height is 40 cm. Given :: radius of base of cylinder= 5 cm height = 40 cm for cylinder , Total surface area of cylinder = 2π r (r+h) =2x3.14x5x(5+40) =2x3.14... 1
- Find the volume of a sphere of diameter 6 cm For the sphere , diameter d=6 cm radius r= diameter/2 = 6/2 =3 Volume of sphere = 4/3π r³ = 4/33.14 x 3³ =113.04 cm³ 1
- Find the volume of a cone if the radius of its base is 1.5 cm and its perpendicular height is 5 cm. The correct Answer is 11.79 cm³ =11.79 cm³ 1