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Finding Lengths on the Coordinate Plane Horizontal & Vertical Lines on a Coordinate Plane Finding Lengths of Horizontal Lines on a Coordinate Plane • Horizontal Lines have the same y-coordinate – Example: (2, 1) and (5, 1) • If points are on the opposite sides of the y-axis, then they have different signs. – Example: (2, 1) and (-3, 1) Horizontal - Points on the Same Side • Points on the same side of the y-axis • Same side = same sign! – To find the length • Count the distance between the x-coordinates (or subtract them) – Example: (2, 1) and (5, 1) • The distance from 2 to 5 = 3, so the distance is 3 units. • 5–2=3 Horizontal - Points on the Opposite Side • Points on the opposite side of the y-axis • Opposite side = Opposite signs – To find the length • Find the Absolute Value of each of the x-coordinates • Add the two absolute values – Example: (2, 1) and (-3, 1) • 2 and -3 are on opposite sides. Absolute values are 2 & 3 • , so the distance between the points is 5 units. Finding Lengths of Vertical Lines on a Coordinate Plane • Vertical Lines have the same x-coordinate – Example: (2, 4) and (2, 9) • If points are on the opposite sides of the x-axis, then they have different signs. – Example: (-5, 4) and (-5, -2) Vertical - Points on the Same Side • Points on the same side of the x-axis • Same side = same sign! – To find the length • Count the distance between the y-coordinates (or subtract them) – Example: (-1, 6) and (-1, 4) • The distance from 4 to 6 = 2, so the distance is 2 units. • 6–4=2 Vertical - Points on the Opposite Side • Points on the opposite side of the x-axis • Opposite side = Opposite signs – To find the length • Find the Absolute Value of each of the y-coordinates • Add the two absolute values – Example: (5, 4) and (5, 2) • Since 4 is a positive and 2 is a negative, the points are on opposite sides of the axis. is 4 + 2 • 4 + 2 = 6, so the distance between the two points is 6 units Lines and No lines Neither Horizontal or Vertical • Points with different x-coordinates and different y-coordinates do not form a horizontal or vertical line. – Example: (-3, 2) and (5, 6) Lie on the X-axis • Points that lie on the x-axis and have a y-coordinate of 0. – Example: (8, 0) and (7, 0) Lie on the Y-axis • Points that lie on the y-axis and have an x-coordinate of 0. – Example: (0, 4) and (0, 10)