You are given the function sin θ = 3/√34. You are asked to find the possible coordinates of point Pp on the terminal arm of θ in the first quadrant. The sine function is equal to the opposite side over the hypotenuse side. Let us assign variables as x, y and r where x is the distance of the line to the x - axis, y is the distance of the line to the y - axis and r is the distance of the hypotenuse line. Apply pythagoreas theorem
r² = x² + y²
(√34)² = x² + 3²
34 = x² + 9
x² = 25
x = 5
the coordinates is placed as (x,y) and you already solved these values and so (5, 3)