How many triangles can be constructed with angles measuring 50º, 90º, and 40º?

If the angles of the triangle are 50, 90, 40 degrees, then only one triangle can be constructed, because if you change the sides the angles would change. 

Period is the time it takes for one “cycle” to complete. in the parent sine function, period is 2*pi since sin(0) = 0, sin(pi/2) = 1, sin(pi) = 0, sin(3pi/2) = -1, and sin(2pi) = 0. at that point, the sequence repeats itself. i’m not sure if your graph is similar to the sine function since you didn’t provide a picture, but you can find the period by looking at a graph.