I am not so great on these questions, but here is a similar question that will definitely help you!
https://smart-answers.com/mathematics/question14195773
Hope this helps!
Area of circle = pi * 4^2 = 16pi (1)
Area of triangle = (1/2)(base) (height) = (1/2)(6) ( 2.5 + 4) = 3 * ( 6.5) = 19.5 (2)
Prob that a point falls in the triangle = (2) / (1) = 19.5 / [ 16pi] = .3879 = .388