Math Help Forum: I need help with a math proof

have to prove these two formulas are equal...

Area of a triangle= 1/2 bc sinA

Area of a triangle= 1/2 bh

Hello, its.all.up.2.u!

Prove:

Code:

            B
            *
           *| *
       c  * |   *   a
         *  |h    *
        *   |       *
       *    |         *
    A *  *  *  *  *  *  * C
               b

We know that the area is: . .[1]

The base of the triangle is side .[2]

In the right triangle at the left: . .[3]


Substitute [2] and [3] into [1]:

. . .