In mathematics, The Pythagorean Theorem is the relationship between three sides of a right triangle.
Step by step guide to solve Pythagorean Theorem problems
- We can use the Pythagorean Theorem to find a missing side in a right triangle.
- In any right triangle: \(\color{buel}{a^2+b^2= c^2}\)
Example 1:
Right triangle ABC has two legs of lengths \(9\) cm (AB) and \(12\) cm (AC). What is the length of the third side (BC)?
Solution:
Use Pythagorean Theorem: \(\color{blue}{a^2+b^2= c^2}\)
Then: \(a^2+b^2= c^2 →9^2+12^2= c^2 →81+144=c^2\)
\(c^2=225 →c=15\) cm
Example 2:
Find the hypotenuse of the following right triangle. 
Solution:
Use Pythagorean Theorem: \(\color{blue}{a^2+b^2= c^2}\)
Then: \(a^2+b^2= c^2 →8^2+6^2= c^2 →64+36=c^2\)
\(c^2=100 →c=10 \)
Example 3:
Find the hypotenuse of the following right triangle.
Solution:
Use Pythagorean Theorem: \(\color{blue}{a^2+b^2= c^2}\)
Then: \(a^2+b^2= c^2 →3^2+4^2= c^2 →9+16=c^2\)
\(c^2=25 →c=5 \)
Example 4:
Right triangle ABC has two legs of lengths \(6\) cm (AB) and \(8\) cm (AC). What is the length of the third side (BC)?
Solution:
Use Pythagorean Theorem: \(\color{blue}{a^2+b^2= c^2}\)
Then: \(a^2+b^2= c^2 →6^2+8^2= c^2 →36+64=c^2\)
\( c^2=100 →c=10\)
Exercises
Find the missing side in each right triangle.
Download Pythagorean Relationship Worksheet
- \(\color{blue}{13}\)
- \(\color{blue}{5}\)
- \(\color{blue}{15}\)
- \(\color{blue}{8}\)
