Activity Overview
In this activity, students use the Geoboard to determine the length of the sides of a right triangles.
Before the Activity
Start the Geoboard App and format it
See the attached PDF file for detailed instructions for this activity
Print pages 85 - 91 from the attached PDF file for your class
During the Activity
Distribute the page to the class.
Follow the Activity procedures:
Draw a right triangle with leg lengths of 1 unit and draw squares on each side of the triangle
Draw right triangles with the different leg lengths given in the table
Draw surrounding squares and record areas of the squares
Find the relationship between the areas of the squares
Understand the Pythagorean Theorem that states - the sum of the square of the length of the legs is equal to the square of the length of the hypotenuse in a right triangle
Draw a right angle triangle with sides 3 and 4 and find the length of the hypotenuse
Note the length is 5 units
Draw four right triangles with length of legs that are different from those used earlier
Enter leg lengths, hypotenuse length, leg length squared, and hypotenuse squared in different columns
Find the relationship between the leg length squared and the hypotenuse squared
Observe that the sum of the leg length squared is equal to the hypotenuse squared and the Pythagorean Theorem is valid in right triangle is A2 + B2 = C2
Given the length of the sides of a triangle identify the triangle as acute, right, or obtuse
If A2 + B2 > C2 then the triangle is an acute triangle
If A2 + B2 = C2 then the triangle is a right triangle
If A2 + B2 < C2 then the triangle is an obtuse triangle
After the Activity
Review student results:
As a class, discuss questions that appeared to be more challenging
Re-teach concepts as necessary