answer: (0, 3)
the y-intercept is where the line intercepts (crosses) the y-axis (up/down axis).
the line crosses the y-axis at 3. when x = 0, y = 3
x = 9
this shape is a 30-60-90 triangle, which means that the angles of the triangle are each 30°, 60° and 90°. given that the measures of the angles of the triangle are known, as well as one side, we can find the measures of all the other sides (example attached). a 30-60-90 triangle is special because of the relationship of its sides. the hypotenuse (directly across from the 90° angle) is equal to twice the length (2x) of the shorter leg, in this case labeled 'x' and directly across from the 30° angle. the longer leg, across from the 60° angle, is equal to multiplying the shorter leg (x) by √3 or x√3.
since the measure of the hypotenuse is given at 18, we can set the expression of that side equal to 18 and solve for x:
2x = 18 or x = 9