Question

Find TSA of cone with radius 4cm and slant height 7cm

Answer 1

TSA of cone = πr(l+r)

$\: \: \: = \frac{22}{7} \times 4cm(7cm + 4cm) \\ \: \: \: = \frac{22}{7} \times 4cm(11cm) \\ \: \: \: = \frac{22}{7} \times 44cm ^{2} \\ \: \: \: = \frac{968cm^{2} }{7} \\ \: \: = 138.28 \: cm^{2} \: \: (approximately)$