Question

Question: Find the area of a triangle whose two sides are 18cm and 10cm respectively and having perimeter 42cm​

Answer 1

Step-by-step explanation:

Let the third side be c.

Given,

a=18 cm. , b= 10 cm. , perimeter = 42 cm.

Perimeter of the triangle = a+b+c.

=> 42 = 18 + 10 + c

=> c = 42 - 28

=> c = 14 cm.

Now,

Semiperimeter = (a+b+c)/2

= (18+20+14)/2

= 21 cm.

Then,

Area of triangle = √{s.(s-a).(s-b).(s-c)}.

= √{21.(21–18)(21–10)(21–14)}

= √{21×3×11×7}

= √{21×21×11}

= 21√11 sq. cm

or

= 69.649 sq.cm

Hope it helps!

Answer 2

Answer:

Step-by-step explanation: