Question

find the area of a triangle two sides of which are 18cm and 10cm and the perimeter is 42​

Answer 1

Step-by-step explanation:

I hope this may help you

Answer 2

Answer:

Perimeter of a Triangle = Sum of 3 sides of a Triangle.......

Step-by-step explanation:

Since,Two of its sides are 18cm and 10cm ......

Let the third side be x,

THEREFORE,

Perimeter = x + 10 + 18;

since Perimeter = 42 (Given).....

therefore: 42 = x + 10 + 18

42 = x + 28

x = 42 - 28

x = 14

So the third side = 14 cm.....

NOW in order to find the area:

A=s(s﹣a)(s﹣b)(s﹣c)

P=a+b+c

s=a+b+c

2

Solving forA

A=1

4﹣P4+4P3a+4P3b﹣4(Pa)2﹣12P2ab﹣

4(Pb)2+8Pa2b+8Pab2=1

4·﹣424+4·423·18+4·423·10

﹣4·(42·18)2﹣12·422·18·10﹣

4·(42·10)2+8·42·182·10+8·42·18·102≈69.64912cm²