- b.Since all of these coordinate pairs have the same y-coordinate
they will all sit three units above the x-axis, forming a horizontal
line. - a.Three noncollinear points determine a plane. Choices band d
are incorrect because •G, •H, and •I do not lie on a common line,
nor can they be connected to form a straight line. Caution: Do not
assume points are noncollinear because they do not share a
common xor ycoordinate. To be certain, plot the points on a
coordinate plane and try to connect them with one straight line. - c.First, find the difference between like coordinates: x 1 – x 2 and
y 1 – y 2 : 4 – (–2) = 6. –5 – 0 = –5. Square both differences: 6^2 = 36.
(−5)^2 = 25. Remember a negative number multiplied by a negative
number is a positive number. Add the squared differences together,
and take the square root of their sum: 36 + 25 = 61. d= 61 . If you
chose choice a, then your mistake began after you squared –5; the
square of a negative number is positive. If you chose choice b, then
your mistake began when subtracting the x-coordinates; two
negatives make a positive. If you chose d, then you didn’t square
your differences; you doubled your differences.
Set 87
- •A (1,6).To locate •A from the origin, count one space right of the
origin and six spaces up. - •B (–4,2.5).To locate •B from the origin, count four spaces left of
the origin and two and a half spaces up. - •C (7,0).To locate •C from the origin, count seven spaces right of
the origin and no spaces up or down. This point lies on the x-axis. - •D (0,–3).To locate •D from the origin, count no spaces left or
right, but count 3 spaces down from the origin. This point lies on
the y-axis, and xequals zero.
501 Geometry Questions