A triangle has sides of lengths 5 cm, 12 cm, and 13 cm. Is it a right triangle?
Practice Questions
Q1
A triangle has sides of lengths 5 cm, 12 cm, and 13 cm. Is it a right triangle?
Yes
No
Cannot be determined
Only if angles are known
Questions & Step-by-Step Solutions
A triangle has sides of lengths 5 cm, 12 cm, and 13 cm. Is it a right triangle?
Step 1: Identify the lengths of the sides of the triangle. They are 5 cm, 12 cm, and 13 cm.
Step 2: Recall the Pythagorean theorem, which states that in a right triangle, the square of the length of the longest side (hypotenuse) is equal to the sum of the squares of the other two sides.
Step 3: Identify the longest side. Here, the longest side is 13 cm.
Step 4: Calculate the square of the longest side: 13 cm squared is 13² = 169.
Step 5: Calculate the squares of the other two sides: 5 cm squared is 5² = 25 and 12 cm squared is 12² = 144.
Step 6: Add the squares of the two shorter sides: 25 + 144 = 169.
Step 7: Compare the sum from Step 6 with the square of the longest side from Step 4: 169 = 169.
Step 8: Since both sides are equal, conclude that the triangle is a right triangle.
Pythagorean Theorem – A theorem that states in a right triangle, the square of the length of the hypotenuse is equal to the sum of the squares of the lengths of the other two sides.