Question

Find cost of polishing a triangular floor design whose sides are 13cm, 14cm and 15cm at the rate rupees 10 per square centimetre.​

Answer 1

Let a=13cm, b=14cm and c=15cm

Now, s=

2

a+b+c

=

2

13+14+15

=21cm

Area:

△=

s(s−a)(s−b)(s−c)

=

21(21−13)(21−14)(21−15)

=

21×8×7×6

=

7×3×2×2×2×7×2×3

=2×2×3×7

=84cm

2

Answer 2

Answer:

Answer -

Let ,

a=13cm,

b=14cm and c=15cm.

Now,

s = a+b+c /2

= 13 + 14 + 15 /2

= 21 cm

Area:

△= √s(s−a)(s−b)(s−c)

= √21(21−13)(21−14)(21−15)

= √21×8×7×6

= √7×3×2×2×2×7×2×3

= 2×2×3×7

= 84cm^2

or 84 square centimetre..