A triangle has sides of length 5 cm,7 cm and 10 cm. Find the area of the triangle (in cm² ).

Correct option is B

Given:

a= 5 cm

b = 7cm

c= 10cm

Formula used:

perimeter = a + b + c

Semi-perimeter = S = (a + b + c)/2

Area of Heron's formula= $$\sqrt{s(s-a)(s-b)(s-c)}$$

Solution:

Perimeter = 5 + 7 + 10 = 22 cm

Semi-perimeter = s = 22/2 = 11 cm

Area of Heron's formula = $$\sqrt{11(11-5)(11-7)(11-10)}$$

= $$\sqrt{11\times 6\times 4\times 1}$$

= 2$$\sqrt{66}$$ $$cm^2$$

Thus, correct option is (b)