Triangle, rectangle, square – Creative Learning

Circumference of geometric shapes: triangle, rectangle, square

Drawing in a square net.
2^nd Grade – Mathematics (Bulgarian educational system)
Based on lesson “Circumference of geometric shapes: triangle, rectangle, square. Drawing in a square net. ”
In Mathematics school book of 2^nd Grade page 53

	Materials for the class Long rope – at least 5, 6 pieces Cardboard with a square net drawn on it – at least 5, 6 pieces Bands – according to the number of students in the class
	Layout of the classroom The desks are aside and there is empty space in the middle.
	Phase 1 The teacher says: “Today we will play the game “Rope Figures” He/she reports that today they will draw geometric figures in an extraordinary way with rope and closed eyes. The game consists of two stages. In the first stage, each group must form a certain geometric figure with the rope, holding the rope with their hands. In the second stage the groups will move their shapes and “draw” them in the square net. The teacher divides the class into several groups of 4 and 5 students depending on their total number. He gives each group a rope. In each group there must be a student who will see and lead the others. The other children in the groups should have blindfolded eyes. A group of 4 students should make a triangle. A group of 5 pupils should make a square or a rectangle.
	Phase 2 The students who can “see” from each group give directions to the other children in the groups. Once each group succeeds in making their figure, the “seers” take the bands from the other children’s eyes. The “seeing” student in each group shows how the circumference of the figure can be measured. Going round his teammates, he says the rule for finding the circumference.
	Phase 3 The teacher places a sheet of cardboard with a square net in front of each team. The groups must “draw” their figure on it. Each team transfers its figure on the square net (approx.). Students are allowed to adjust the rope by the squares. The groups “draw” their rope figure along the squares.
	Phase 4 The teacher says that each square from the square net is 1m long. Each group has to find the circumference of the figure it has drawn with the rope on the cardboard. The students have to find the length of the sides of their “rope” figures first and then find their circumference. The game ends when each group finds the circumference of their figure.