Organize students into groups of four or five. Discuss the terms
right angle, triangle, sides, and hypotenuse with
Ask students in each group to use cardboard to make cutouts of
Tell students to measure the sides and hypotenuse of each triangle
to the nearest millimeter and convert the measurements to centimeters.
Challenge students to observe their triangles and work in their
groups to discover a relationship between the two sides and the
hypotenuse of the triangles. Let them think of all the possible
ways of relating the three sides. Allow them to make extensive use
As soon as students find the relationship between the two sides
and the hypotenuse, have them tabulate the following information
for each triangle in their group:
- Measurements of sides a, b, and hypotenuse c
- Computations: squares of a, b, and c
- Relationship observed
Students should observe that the square of the hypotenuse is equal
to the sum of the squares of the other two sides. Tell them that
this is known as Pythagorean Theorem or the Theorem of
Pythagoras. Also, discuss the converse of the theorem. Tell
students that these three positive integers a, b, and c
are called a Pythagorean triplet.
This activity will provide a practical application of the Pythagorean
- Bring a ladder to the classroom and ask students to measure
its length. Place the ladder against a wall and measure the distance
between the foot of the ladder and the wall. Challenge students
to determine how high on the wall the ladder reaches.
each group to put their heads together to come up with a problem that
would challenge others to apply the theorem. Does each group come
up with an appropriate problem? Which group created the most unique
Jeet Makkar, Salwan Public School, New Delhi, Delhi (India)
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