Chapter 7 Mensuration Class 10 Maharashtra Board TextBook Solution
Practice set 7.1 | Q 8 | Page 145
In the given figure, a cylindrical wrapper of flat tablets is shown. The radius of a tablet is 7 mm and its thickness is 5 mm. How many such tablets are wrapped in the wrapper?
Answer:-
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 the slant height of the cone be l cm.
Therefore, l = sqrt(r^2 + h^2) = sqrt(3^2 + 4^2) = sqrt(9 + 16) = sqrt(25) = 5 cm
Total area of the toy = Curved surface area of hemisphere + Curved surface area of cylinder + Curved surface area of cone
= 2πr^2 + 2πrH + πrl = 2π x (3)^2 + 2π x 3 x 40 + π x 3 x 5 = 18π + 240π + 15π = 273π cm^2
Thus, the total area of the toy is 273π cm^2.
Solution
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 the slant height of the cone be $l$ cm.
$$therefore l = sqrt{r^2 + h^2} = sqrt{3^2 + 4^2} = sqrt{9 + 16} = sqrt{25} = 5 text{ cm}$$
Total area of the toy = Curved surface area of hemisphere + Curved surface area of cylinder + Curved surface area of cone
$$ = 2pi r^2 + 2 pi rH + pi rl$$
$$ = 2pi times (3)^2 + 2pi times 3 times 40 + pi times 3 times 5$$
$$ = 18pi + 240pi + 15pi$$
$$ = 273pi {cm}^2$$
Thus, the total area of the toy is $273pi$ cm2.
Chapter 7 Mensuration Textbook Solution 7.1
Practice set 7.1
Click Here for all Textbook Answers of Chapter 7 Mensuration