Hi, I am have trouble with this problem. Find the area of triangle with angles 45-15-120. The side across from the 120 degree angle is 10. I need to solve without Trig. Similar problems have found 30-60-90 or 45-45-90 triangles in problem and used them to find the solution. But I am stumped....Ed

How did they solve the ones with 30-60-90 triangles and 45-45-90 triangles? Can you extend one of the sides forming the 120-degree angle, drop the perpendicular from the vertex on that side, and form a 30-60-90 triangle along that side, and do anything with that? Like, for a start, the height of the 30-60-90 triangle would be the height of the 15-45-120 triangle, too.Hi, I am have trouble with this problem. Find the area of triangle with angles 45-15-120. The side across from the 120 degree angle is 10. I need to solve without Trig. Similar problems have found 30-60-90 or 45-45-90 triangles in problem and used them to find the solution. But I am stumped....Ed