Prentice Hall Geometry
  1. Sierpinski's Triangle Sierpinski's triangle is a famous geometric pattern. To draw Sierpinski's triangle, start with a single triangle and connect the midpoints of the sides to draw a smaller triangle. If you repeat this pattern over and over, you will form a figure like the one shown. This particular figure started with an isosceles triangle. Are the triangles outlined in red congruent? Explain.

    A Sierpinski triangle has lines from the midpoints of two sides of the largest triangle connecting at the midpoint of the bottom side, forming two triangles at the bottom corners, with the two angles between the sides of the original triangle equal.

  2. Constructions Use a straightedge to draw any triangle JKL. Then construct cap delta m n p approximately equal to cap delta j k l  using the given postulate.
    1. SSS
    2. SAS

Can you prove the triangles congruent? If so, write the congruence statement and name the postulate you would use. If not, write not enough information and tell what other information you would need.

  1. Between triangles AGN and RTW, angles N and W are equal, sides NA and WR are equal, and sides NG and WT are equal.
  2. Between triangles HDY and PTK, sides HD and PT are equal and sides HY and PK are equal.
  3. Triangles EFJ and VFS share vertex F, with sides EJ, FJ, FS, and VS equal and sides EF and VF equal.
  4. Reasoning Suppose g h bar , approximately equal to . j k bar , comma . h i bar , approximately equal to . k l bar , comma  and angle i approximately equal to . angle l .  Is cap delta g h i  congruent to cap delta j k l .  Explain.
  5. Proof Given: g k bar  bisects angle j g m comma . g j bar , approximately equal to . g m bar

    Prove: cap delta g j k approximately equal to cap delta g m k

    Triangles GJK and GMK share side GK, with sides GJ and GM equal.

  6. Proof Given: eh e bar  and b d bar  bisect each other.

    Prove: cap delta eh c b approximately equal to cap delta e c d

    Triangles ACB and ECD share vertex C.

  7. Proof Given: f g bar , box drawings double vertical . k l bar , comma . f g bar , approximately equal to . k l bar

    Prove: cap delta f g k approximately equal to cap delta k l f

    Triangles FGK and KLF share side FK with sides FG and KL equal and parallel.

  8. Proof Given: eh b bar , up tack . c m bar , comma . eh b bar , up tack . d b bar , comma . c m bar , approximately equal to . d b bar , comma

    M is the midpoint of eh b bar

    Prove: cap delta eh m c approximately equal to cap delta m b d

    Triangles AMC and MBD share vertex M, with angles AMC and MBD each a right angle and sides MC and BD equal.


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Table of Contents

Prentice Hall Geometry Chapter 1 Tools of Geometry Chapter 2 Reasoning and Proof Chapter 3 Parallel and Perpendicular Lines Chapter 4 Congruent Triangles Chapter 5 Relationships Within Triangles Chapter 6 Polygons and Quadrilaterals Chapter 7 Similarity Chapter 8 Right Triangles and Trigonometry Chapter 9 Transformations Chapter 10 Area Chapter 11 Surface Area and Volume Chapter 12 Circles Skills Handbook Reference Visual Glossary Selected Answers Index Acknowledgments