What is the area in square units of the quadrilateral $XYZW$ shown below? Also, find $WY$.
Semiperimeter of top triangle = 19/2 = 9.5
Semiperimeter of bottom triangle = 20/2 = 10
Area = sqrt [ 9.5 ( 9.5 - 9) (9.5 - 7) (9.5 -3) ] + sqrt [ 10 (10 - 9) (10 -6) (10 - 5) ] =
sqrt [ 9.5 * .5 * 2.5 * 6.5 ] + sqrt [ 10 * 4 * 5 ] =
sqrt [ 77.1875 ] + sqrt [ 200] ≈ 22.93
WY (by graph) ≈ 5.34