Based from the given slope of 1/2 and a y-intercept of -6, our equation of a line is y=x/2 -6. To remove the fraction we can multiply the equation by 2 to get 2y=x-12. Using this substitute the value of y coordinate 4.
let's notice that, each angle has an "angle tickmark", indicating that all three angles are equal, thus is an equilateral triangle, since the sides are equal, then