Yes, a plane is a one dimensional figure
The answer is 4 of the set
The angle is in the second quadrant so only the sine is positive .
Length of the hypotenuse = sqrt (-1^2 + 3^2) = sqrt10
sine = 1/sqrt10 = 0.3162 to 4 dec places
tangent = 1 / -3 = -0.3333 to 4 d p's
cosine = -3/sqrt10 = -0.9487 to 4 d, p's.
