Activities on Perimeter & Area(A)

< 25.2 Area | Topic Index | 25.4 Volume &amp; Surface Area >

These activities are for understanding the inter-relation area &amp; perimeter concepts


 * 1) Take a rectangular piece of thick chart paper 				Cut it along the diagonal into 2 pieces – what can you say about these 2 shapes (right angled scalene triangles, both are congruent)Join both the pieces in as many ways as possible, keeping in mind that  					The 2 pieces should not overlapThe resulting shape should only be a 3 or 4 sided figure  				How many different shapes have you been able to get?Can you name these shapes? (2 isosceles triangles, 1 rectangle, 2 parallelograms, 1 kite)Can you define the properties of these shapes?</li>Can you name a property which all these shapes share? (area)</li>Can you name a property which these shapes do not share? (perimeter)</li><a name="_Hlk15982128">(Can you arrange the figures in increasing order of their perimeters)</a></li></ol>
 * 2) Cut a scalene triangle 				Fold it into a rectangle</li>Find out the area of the triangle</li></ol>
 * 3) Cut 4 congruent scalene triangles 				Prove that 3 angles of a triangle is a straight angle</li>Arrange the 4 triangles so that they form a larger but similar triangle</li>From the above arrangement, find out how to cut any triangle into 4 smaller similar triangles</li></ol>
 * 4) Cut a long rectangular piece of paper which looks like a ribbon. 				Gently fold a pentagon by tying a knot in the ribbon</li></ol>
 * 5) Draw a circle 				Keeping the arms of a compass equal to the radius of the circle, mark off equal points on the circumference</li>Join every point to the next point. What shape do you get? (Hexagon)</li>Join every point to every other point.</li><li>What other shapes do you see? (Equilateral triangles, rhombus/ parallelogram, trapezium)</li><li>Find the sum of the angles in any of the triangles &amp; quadrilaterals.</li><li>What is the perimeter of the large shape? (6R)</li><li>So what can you say about the circumference of the circle in comparison to the perimeter of the large shape?</li></ol>
 * 6) Take 5 squares of equal size made from cardboard<ol style="margin-top:0;margin-bottom:0;"> 				<li>Join all the 5 squares into various shapes, keeping in mind that<ol style="margin-top:0;margin-bottom:0;">  					<li>Any square should at least touch one other square along one side</li><li>&ldquo;Touching&rdquo; means touching along the entire side. Touching partially is not allowed</li><li>Touching just at the corners is not allowed.</li></ol>  				</li><li>Each of these shapes is called a Pentomino. Penta means 5.</li><li>On a dotted sheet, drawn each of the pentominoes you get</li><li>What is the total number of shapes you can get? (12)</li><li>Which of these pentominoes, if drawn on paper, can be folded into an open box?</li><li>What is a property which is common to all these pentominoes? (area)</li><li>Which is a property which all these pentominoes do not share? (perimeter)</li><li>(Can you arrange the figures in increasing order of their perimeters)</li></ol>
 * 7) Take the set of triangles (this has to be prepared in advance)<ol style="margin-top:0;margin-bottom:0;"> 				<li>Can you find if there are 2 triangles which are congruent?</li><li>Can you find out if there are 2 triangles which are similar to each other?</li></ol>
 * 8) Take the set of rectangles (this has to be prepared in advance)<ol style="margin-top:0;margin-bottom:0;"> 				<li>Without measuring, can you find out if there are 2 rectangles which are similar to each other? (If we keep the 2 similar rectangles overlapping and touching at one of the corners and along the 2 sides, their diagonals will coincide.</li></ol>

< 25.2 Area | Topic Index | 25.4 Volume &amp; Surface Area >