The formula for the area of a triangle is Because the area is
given as 15 square units, and the height is 5 − 2 = 3 units, the base must
be 10 units long. Refer to the drawing above and see that the length for
the base is the difference between the x-coordinate of (1,2) and the x-
coordinate of (k,2). The base can therefore be represented as k − 1, or 1 −
k. Therefore, k = 11, or k = −9.50 . A
The problem shows a right triangle in which an angle measure and the
length of the hypotenuse are known. Use trigonometry to find the length
of , the opposite side of the 42° angle. Using x to represent the length
of ,