Two angles that are opposite and equal to each other when two lines cross are called angles.

Express the following as a function of a single angle, cos(60) cos(-20) - sin(60) sin(-20)

In a graph with several intervals o data how does a constant interval appear? what type of scenario produces a constant interval?

David is spreading mulch on a triangular area of his flower bed. the coordinates of the vertices of the area are (1, 3), (9, 3), and (4, 6). what is the area of the triangle if each square has an area of 3 square feet?