Originally Posted by
ticbol Plenty. I do not have all the time now because my attention is on the Super Bowl XL (it's halftime now, my team, Steelers, leading 7 to 3. Zeez, we are just lucky. Our quarterback is nervous. But I see that when the 2nd half resumes, he will explode, meaning, wake up, and he'll kill 'em Seahawks. Man!).
1) Get the lengths of the 3 sides by distance between two points (x1,y1) and (x2,y2) is sqrt[(x2 -x1)^2 +(y2 -y1)^2]. Then use the Heron's formula. One way.
2) Enclose the triangle by a rectangle. Area of triangle equals area of rectangle minus the areas of the 3 right triangles enclosing the said triangle. Way #2.
3) Get the 3 altitudes. Then area = (1/2)(altitude)(base). Ways #3,4,5.
4) Get the 3 interior angles. Then area = (1/2)(side)(another side)*sin(included angle). Ways #6,7,8.
5)Get the inradius. Then area = (1/2)(inradius)(perimeter of triangle). Way #10.
6) Then there is one formula using the circumradius. Way #11.
Many more, maybe, but cannot concentrate on them now....
The Living Deads (aka The Rolling Stones) just finished spooking the festivities. Second Half of the Game coming up. See ya later...