Diameter, d = 10.5cm

Radius, r = \(\frac{10.5}{2}\) cm = 5.25 cm
Slant height, l = 10 cm
Curved surface area = \(\pi rl\)
\(= \frac{22}{7} × 5.25 × 10\)
= 165 cm²
Thus, curved surface area of the cone = 165 cm².
(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.
