You need numbers from the sides of the triangles. Take numbers from the corresponding (matching) sides, one number from the small triangle, and one number from the big triangle. Then divide the big...
Yes! A scalene triangle is one where none of the 3 sides are equal. An obtuse triangle is one where one of the angles is greater than 90 degrees. So, for example, a triangle whose angles were 100, 45...
The 2 triangles can be of any type (e.g isosceles, equilateral, etc.), only they must be exactly the same if they are congruent, i.e one triangle must be an exact copy of the other one.