Question

The area of triangle with given two sides 13 cm and 9 cm respectively and perimeter equal to 42 cm is: ​

Answer 1

Answer:

44.899cm²= 44.9cm²

Step-by-step explanation:

perimeter of triangle = a+b+c = 42

= 13+9+c=42

=>c=42-22 = 20 cm

s= (a+b+c)/2 = (13+9+20)/2

= 42/2 = 21cm

Area of triangle = √s(s-a)(s-b)(s-c)

= √21(21-13)(21-9)(21-20)

= √(21×8×12×1)

= √2016

= 44.899 cm² = 44.9cm² ≈ 45cm²