Thread: Triangle Area

Prove that the area of triangle ABC is given by the formula:

Area of triangle ABC = 1/2 * AB * AC * sin(angle BAC)

Code:

        b *
         /|\
        / |  \
       /  |h   \
      /   |      \
     /    |        \
  a*----------------*c

(First time using this code to draw diagrams)

Lets use this triangle as an example.

h = height

Area of a triangle = 1/2 * base * height

Base = length AC
Height = length AB * sin (angle BAC)

Therefore area of triangle = 1/2 * AC * AB * sin(angle BAC)

I had to prove this when I was learning trigonometry as well.