To answer this question remember that each angle in a rectangle is 90 degrees and there are 180 degrees in a triangle. Look at the figure. When presented with a shape like this, look for shapes that are familiar. The rectangle has been divided into 4 separate triangles. Three of the triangles have one side of the triangle that is represented by the angle of the original rectangle. For example, a triangle is represented by the angles of a and b as well as the 90 degree angle that is represented by point S. Since there are 180 degrees in a triangle, and 90 of those degrees are found at point S, the sum of angles a and b is 90. The same principle can be applied to the triangle that is created by angles c, d, and point T, as well as the triangle created by angles e, f, and point U. Since this is true, c + d = 90 and e + f = 90. Therefore, the sum of all the angles is 270.