GEOMETRY HELP Draw all lines of symmetry for an isosceles trapezoid. Draw an isosceles trapezoid. Then draw any lines that divide the isosceles trapezoid so that half of the figure is a mirror image of the other half. There is one line of symmetry. Quick Check Symmetry LESSON 9-4 Additional Examples

GEOMETRY HELP Judging from appearance, do the letters V and H have rotational symmetry? If so, give an angle of rotation. The letter V does not have rotational symmetry because it must be rotated 360° before it is its own image. The letter H is its own image after one half-turn, so it has rotational symmetry with a 180° angle of rotation. Symmetry LESSON 9-4 Additional Examples Quick Check

GEOMETRY HELP A nut holds a bolt in place. Some nuts have square faces, like the top view shown below. Tell whether the nut has rotational symmetry about a line and/or reflectional symmetry in a plane. The nut has a square outline with a circular opening. The square and circle are concentric. The nut is its own image after one quarter-turn, so it has 90° rotational symmetry. The nut has 4 lines of symmetry. Symmetry LESSON 9-4 Additional Examples Quick Check