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Home > GC > Chapter 2 > Lesson 2.1.1 > Problem 2-11

2-11.

Jerry has an idea. Since he knows that an isosceles trapezoid has reflection symmetry, he reasons, “That means that it must have two pairs of angles with equal measure.” He marks this relationship on his diagram below.

Copy the shapes below onto your paper. Similarly mark which angles must have equal measure due to reflection symmetry.  

Isosceles trapezoid with reflection symmetry down the middle such that the left side is a mirror image of the right side.

  1. 4 sided polygon, labeled Kite, with sides labeled as follows: left top & left bottom sides, 1 tick mark, right top & right bottom sides, 2 tick marks.
    KITE

  1. Triangle labeled Isosceles triangle, with sides labeled as follows: left & right sides, 1 tick mark.
    ISOSCELES TRIANGLE

  1. Regular Hexagon
    REGULAR HEXAGON

  1. Rhombus
    RHOMBUS

Draw all lines of symmetry.

Mark the angles that correspond and are on opposite sides of the line of reflection.