Question

find the area of a triangle whose sides are 28 cm, 21 cm and 35 cm​

Answer 1

294 sq. cm

Step-by-step explanation:

Let a,b,c be the lengths of the sides of a triangle. The area is given by:

Area = √p(p−a) (p−b) (p−c)

where p is half the perimeter, or a+b+c/2

p = 28+21+35/2 = 84/2

= 42 sq cm.

Area = √42 (42-28) (42-21) (42-35)

= √42 (14) (21) (7)

= √42x14x21x7

= √86,436

= 294 sq. cm