# Coordinates and the Area Addition Postulate Exercises

### Example 1

What is the area of a triangle contained by the points *A* (0, 0), *B* (7, 0), and *C* (0, 4)?

### Example 2

A right triangle has an area of 60 units^{2}. If the vertex of its right angle is at the origin and it has another vertex at (12, 0), where can its final vertex be plotted?

### Example 3

A circle has a center at (4, -3) and a point *P* (0, 0). What is the area of the circle?

### Example 4

A trapezoid has vertices (corners) at the points *A* (0, 0), *B* (0, 10), *C* (12, 4), and another point *D*. If the area of the trapezoid is 48 units^{2} and *AB* is one of the bases, what are the coordinates of *D*?

### Example 5

The diameter of a circle reaches from (-1, 9) to (3, 3). What is the area of the circle?