(i) Radius of sphere = 7 cm
Volume of sphere =\(\frac{4}{3}\pi r^3\)
= \(\frac{4}{3}\) × \(\frac{22}{7}\) × 7 cm × 7 cm × 7 cm
\(= \frac{4312}{3}\) cm3
= 1437.33 cm3
Therefore, the volume of the sphere is 1437 cm3 .
(ii) Radius of sphere = 0.63 m
Volume of sphere =\(\frac{4}{3}\pi r^3\)
= \(\frac{4}{3}\) × \(\frac{22}{7}\) × 0.63 m × 0.63 m × 0.63 m
= 1.047816 m3
= 1.05 m3 (approx.)
Therefore, the volume of the sphere is 1.05 m3 (approximately).
(i) The kind of person the doctor is (money, possessions)
(ii) The kind of person he wants to be (appearance, ambition)
ABCD is a quadrilateral in which AD = BC and ∠ DAB = ∠ CBA (see Fig. 7.17). Prove that
(i) ∆ ABD ≅ ∆ BAC
(ii) BD = AC
(iii) ∠ ABD = ∠ BAC.
