## anonymous one year ago This question is based on Heron's Formula : In a triangle ABC, it is given that (s - a) = 5, (s - b) = 3, (s - c) = 1 where s is the semi perimeter and a, b, c are the sides of the triangle. If the area of the triangle is 3sqrt10 sq. units then the perimeter of the triangle is what???

1. phi

first, write down Heron's formula

2. anonymous

$Area = \sqrt{s(s-a)(s-b)(s-c)}$

3. phi

now fill in what you know (from the question)

4. anonymous

I substituted vales and found s=6 but it does not work ......

5. phi

s= is (a+b+c)/2 a+b+c is the perimeter you want 2*s for the answer

6. anonymous

I have already tried by substituting values and got s=6 but it is not correct

7. anonymous

Options for answer are: a) sqrt15 b) 9 c) 27 d) 18

8. phi

in that case you are the victim of a typo, because the perimeter is 12

9. anonymous

but if you take s=6 and find values of a, b and c and then find s by a+b+c/2, you get a different value of s

10. phi

even worse, we find a=1, b= 3 and c= 5 and that cannot be a triangle. (c must be less than 4 to be a triangle)

11. anonymous

Right!! I was wondering whether I was wrong in my process or was there a mistake in the question itself.........

12. phi

there is something wrong with the question, as it poses an impossible situation I assume there is a typo in the original givens, but it is difficult (for me) to guess what they really meant.

13. anonymous

14. phi