Question

35. An umbrella is made by stitching 12
triangular pieces of cloth, each measuring
(50 cm x 20 cm x 50 cm). Find the area of
the cloth used in it.
​

Answer 1

Answer:

(Area of 1 ∆ular piece of cloth)--- s

= 50+20+50/2=60. Now, using Heron's formula--- Area=

√s(s-a)×(s-b)(s-c) =√60(60-50)(60-20)(60-50) =√60×10×40×10

= √30×2×5×2×2×20×5×2

=√2×3×5×2×2×5×2×2×2×5×5×2=

200√6 cm².

Therefore, area of cloth used

= 200√6×12=

5878.77cm².