Group Activity Cards

 Use groups of 2. Materials: Spinner, 20 index cards, compass, protractor, ruler Relating the Triangles

Divide the spinner into 3 equal-sized sections. Label the sections Similar, Congruent, and Neither. Give each player 10 index cards. Player 1 begins by spinning the spinner and taking two index cards. If the spinner lands on Similar, then using a compass, protractor, and ruler, player 1 should draw two similar triangles, one per card. Player 1 should label the length of the sides and the angle measures. Player 2 should check the answer. Next, player 2 spins the spinner and follows the same procedure. Make sure that no two cards have identical triangles.

When all cards have been drawn and checked, place them all together. Shuffle the cards and place them face down on the table in 5 × 4 rectangular array. Player 2 begins this round by spinning the spinner and flipping two cards over. If the spinner lands on Similar, then player 2 will have a match if the two cards turned over are similar triangles. If player 2 gets a match, he or she keeps the two cards. If the two cards do not match then the cards are turned back over. Next, player 1 spins the spinner and turns two cards over. Continue playing until all cards have been taken or there are no more matches.