Areas and Perimeters
If the quadrilateral is divided horizontally through the line y = 2, two congruent triangles are formed.
As the figure shows, the top triangle has height 2 and base 4.
Hence, its area is
The area of the bottom triangle is the same, so the area of the quadrilateral is 4 + 4 = 8.
The answer is (D).
Point A has coordinates (0, 4), point B has coordinates (3, 0), and point C has coordinates (5, 1).
Using the distance formula to calculate the distances between points A and B, A and C, and B and C yields
Adding these lengths gives the perimeter of Triangle ABC:
The answer is (A).