XY = 6
YZ = 12
Area of triangle = 1/2 x base x height
Area of triangle = 1/2 x XY x YZ
= 1/2 x 6 x 12
= 3 x 12
= 36
The area of triangle XYZ is 36 square units.
The area of triangle XYD is at most 20
P(at most 20) = 20 / 36
= 5 / 9
The probability that area of triangle XYD is at most 20 is 5 / 9
5 / 9