The diagram shows a shaded parallelogram drawn inside a rectangle. 3 cm
b)
А
c)
6 cm
d)
B
+3 cm
-12 cm
a) What is the area of the rectangle?
b) What is the area of triangle A?
c) What is the area of triangle B?
d) What is the area of the parallelogram?

These are the multiples of 15 but what you are probably asking or what are the factors of 15

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.