Question

Help!
should I use the law of cos than find the area?
find the area of the triangle with the sides of 3,9, and 10

Answer 1

Use Heron's formula:

If you have a triangle with sides, a, b, c, then:

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

\(s = \dfrac{a + b + c}{2}\)

Answer 2

Is there another way to do this?

Answer 3

There's always more than one way to do any mathematics.

Answer 4

Well, what is another way to do this? @Hero

Answer 5

Find the height of \(d\), then you'd be able to use \(A_{\triangle} = \frac{bh}{2}\)