Question

Calculate
(a) Area of square having side is 2.15m.
(b) Volume of sphere of radius is r=4 m.
(c) Density of a solid whose mass is 21.035 g and volume 3.14 cm^3
(d) Length of rectangle, having area 12.5 cm^2 and breadth 3.5 cm.
(e) Area of circle is 65 cm^2 so radii.​

Answer 1

Answer:

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Explanation:

Answer :-

a) Area of square = ( side ×side )

$side \: of \: the \: square \: = 2.15m \\ area \: of \: the \: square \: = (2.15) {}^{2} \: sq.m \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = 4.6225 \: sq.m$

$b) \: \: volume \: of \: sphere \: = \frac{4}{3} \pi {}r^{3}$

$radius \: of \: the \: sphere \: is \: r = \: 4m \\ volume \: = \frac{4}{3} \pi{}r^{3} \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \ = \: \frac{4}{3} \times \frac{22}{7} \times (2) {}^{3} \: m {}^{3} \\ \: \: \: \: \: \: \: \: \: \: \: \: \: = 33.51m {}^{3} (approximate)$

$c) \: \: density \: = \frac{mass}{volume} \\ mass \: of \: the \: solid \: is \: 21.035g \: \\ and \: volume \: is \: 3.14 \: cm {}^{3} \\ volume \: = \frac{21.035}{3.14} \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = 6.69904459 \: g \: cm {}^{ - 3}$

d) Area of Rectangle is = length × breadth

$area \: of \: rectangle \: = 12.5 \: cm {}^{2} \\ breadth \: of \: rectangle \: = 3.5 \: cm \\ let \: \: length \: \times breadth \: = area \\ or \: l \times 3.5 = 12.5 \\ or \: l \: = \frac{12.5}{3.5} = 3.57142857cm$

$e) \: \: area \: of \: circle \: is \: \ \pi{}r^{2} \\ let \: \pi {}r^{2} = 65 \: cm {}^{2} \\ or \: \: r {}^{2} = \frac{65 \times 7}{22} \\ or \: \: r \: = \: 4.55 \: cm \: (appr)$