Distance of a point from a line
Two-dimensional geometry · Mathematics
Study notes
Q: Find the distance from (3,4) to the line 3x + 4y - 24 = 0. Which side of the line is the origin on? d = |3(3)+4(4)-24|/sqrt(9+16) = |9+16-24|/5 = 1/5 = 0.2. Signed value at origin: (0+0-24)/5 = -4.8 < 0; at (3,4): +0.2 > 0. Opposite signs, so the origin and (3,4) lie on opposite sides of the line.