The equation of a line containing one leg of a right triangle is y=-4x. Write equations could represent the line contains the other leg?

Any line with a slope of (1/4).

In a right triangle, one pair of legs must form a right angle. When two lines form a right angle, we say that they are perpendicular.

If the slope of a line is - 4, the slope of a perpendicular line is (1/4).