geometry

posted by .

We are learning about proofs. We drew lines between noncollinear points. Our table showed 2 points >> 1 line segment, 3 point >> 3 line segments, 4 points >> 6 line segments, 5 points >> 10 line seg, 6 points >> 15 line seg. etc.

Write an expression in terms of n for the number of line segments that can be drawn between n points.

Please help.

  • geometry -

    1, 3, 6, 10,.. is the series
    N*(N-1)/2
    where N is the number of points.

    These are sometimes refered to as triangle numbers. (This of stacking pop cans in a triangle with rows of 1, 2, 3, 4 etc.)

    See http://en.wikipedia.org/wiki/Triangular_numbers

  • geometry -

    Thank you very much. I could explain it (I thought) but couldn't express it in math terms. Thanks again

  • geometry -

    line segment 6cm and divide 5 congruent parts

  • geometry -

    A circle is described by the equation x2 + y2 + 14x + 2y + 14 = 0. What are the coordinates for the center of the circle and the length of the radius?

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. math

    you can draw one segment to connect two points and three distinct segments to connect three named points. how many segments can you drawto connect five points if no three of the points lie on the same line.........please help me i …
  2. math

    you can draw one segment to connect two points and three distinct segments to connect three named points. how many segments can you drawto connect five points if no three of the points lie on the same line.........please help me i …
  3. geometry

    Trisha drew a pair of line segments starting from a vertex. Which of these statements best compares the pair of line segments with the vertex?
  4. Math Geometry

    A cube has 8 vertices. For each pair of distinct vertices, we connect them up with a line segment. There are (8) (2) =28 such line segments. For each of these 28 line segments, we mark the midpoint. How many distinct points have been …
  5. Geometry

    Kelly drew four points A, B, C, and D in her notebook. A straight line joins points A and C. Another straight line joins A and B. A point D is located on the left of the line AB Kelly made the following statements about the points. …
  6. math

    Ten distinct noncollinear points are chosen on a plane. a) How many line segments can be formed by joining any two of these points?
  7. Math

    We are learning about proofs. We drew lines between noncollinear points. Our table showed 2 points >> 1 line segment, 3 point >> 3 line segments, 4 points >> 6 line segments, 5 points >> 10 line seg, 6 points …
  8. Math

    A line 'l' intersects line 'm' at point A at 45 degree angle. B and C are points on line m, where the distance from B to A is equal to the distance from A to C. How many points on line 'l' are equidistant from points B and C?
  9. math

    X1, X2,...,X9 are nine points on the circumference of circle O. Line segments are drawn connecting each pair of points. What is the largest number of different points inside the circle at which at least two of these line segments intersect?
  10. Geometry

    I have another question that stumped me Line segment AB with length a is divided by points P and Q into three line segments: AP , PQ, and QB , such that AP = 2PQ=2QB. Find: A)the distance between point A and the midpoints of the segments …

More Similar Questions