Group Activity Cards
Use groups of 2.
Materials: 16 index cards, protractor, ruler

Common Triangles 
Each group member should have 8 index cards. On 4 of the index cards, group members should draw different triangles, one triangle per card. Label the lengths of the sides in centimeters and the measures of the angles in degrees. On the other 4 index cards, group members should draw 4 different quadrilaterals. Label the length of the sides in centimeters and the measures of the angles in degrees.
Combine your triangle cards. As a group, place the eight triangles into categories. The categories may be according to any category you choose. Some suggestions are size, angle measure, lengths of sides, or types of angles. Record your categories and write them on each card.
Next, combine your quadrilateral cards. Place the eight quadrilaterals into categories and record the categories on the cards.
Finally, as a class, compare categories. Did any groups use the same categories?
