Pythagorean Theorem Worksheet With Answers

Mastering the Pythagorean Theorem: A Comprehensive Worksheet with Answers and Explanations

The Pythagorean Theorem is a fundamental concept in geometry, forming the cornerstone of many mathematical applications. Understanding this theorem is crucial for anyone pursuing studies in mathematics, physics, engineering, or even architecture. This comprehensive worksheet provides a range of problems, from simple applications to more complex scenarios, designed to solidify your understanding of the theorem and its practical applications. Each problem includes a detailed solution, enabling you to check your work and identify areas requiring further attention. Let's dive in!

Understanding the Pythagorean Theorem

The Pythagorean Theorem states that in a right-angled triangle, the square of the hypotenuse (the side opposite the right angle) is equal to the sum of the squares of the other two sides (called legs or cathetus). Mathematically, this is expressed as:

a² + b² = c²

Where:

• a and b represent the lengths of the two shorter sides (legs) of the right-angled triangle.
• c represents the length of the hypotenuse (the longest side).

This simple equation allows us to calculate the length of any side of a right-angled triangle if we know the lengths of the other two sides. This has profound implications in various fields, enabling us to solve problems related to distances, heights, and angles.

Pythagorean Theorem Worksheet: Problems and Solutions

This worksheet is designed to progressively challenge your understanding of the Pythagorean Theorem. Start with the easier problems and gradually work your way up to the more complex ones. Remember to show your work for each problem – this is crucial for understanding the process and identifying any mistakes.

Section 1: Basic Applications

Problem 1: A right-angled triangle has legs of length 3 cm and 4 cm. Find the length of the hypotenuse.

Solution:

Using the Pythagorean Theorem: a² + b² = c²

3² + 4² = c²

9 + 16 = c²

25 = c²

c = √25 = 5 cm

Therefore, the length of the hypotenuse is 5 cm.

Problem 2: A right-angled triangle has a hypotenuse of length 10 m and one leg of length 6 m. Find the length of the other leg.

Solution:

Using the Pythagorean Theorem: a² + b² = c²

a² + 6² = 10²

a² + 36 = 100

a² = 100 - 36

a² = 64

a = √64 = 8 m

Therefore, the length of the other leg is 8 m.

Problem 3: A ladder leans against a wall. The base of the ladder is 5 feet from the wall, and the top of the ladder reaches 12 feet up the wall. How long is the ladder?

Solution:

This problem describes a right-angled triangle where the ladder is the hypotenuse.

a = 5 feet (distance from the wall) b = 12 feet (height up the wall) c = length of the ladder

Using the Pythagorean Theorem: a² + b² = c²

5² + 12² = c²

25 + 144 = c²

169 = c²

c = √169 = 13 feet

Therefore, the ladder is 13 feet long.

Section 2: Intermediate Applications

Problem 4: A rectangular field measures 20 yards by 30 yards. What is the length of the diagonal across the field?

Solution:

The diagonal of a rectangle forms the hypotenuse of a right-angled triangle.

a = 20 yards b = 30 yards c = length of the diagonal

Using the Pythagorean Theorem: a² + b² = c²

20² + 30² = c²

400 + 900 = c²

1300 = c²

c = √1300 ≈ 36.06 yards

Therefore, the length of the diagonal is approximately 36.06 yards.

Problem 5: A ship sails 15 km due east, then 20 km due north. How far is the ship from its starting point?

Solution:

The ship's journey forms two legs of a right-angled triangle, with the distance from the starting point being the hypotenuse.

a = 15 km b = 20 km c = distance from starting point

Using the Pythagorean Theorem: a² + b² = c²

15² + 20² = c²

225 + 400 = c²

625 = c²

c = √625 = 25 km

Therefore, the ship is 25 km from its starting point.

Problem 6: Two sides of a right-angled triangle are 7 cm and 24 cm. Find the length of the third side. (Hint: Consider whether the given sides are the legs or if one is the hypotenuse.)

Solution:

Since we have two sides, we can use the Pythagorean Theorem to find the third side. Let's assume one of these sides is the hypotenuse and find if it is correct by applying the theorem.

Scenario 1: 7 cm is the hypotenuse.

7² = a² + 24² This results in a negative value for a², which is impossible since a² must be positive. Thus, 7 cm is not the hypotenuse.

Scenario 2: 24 cm is the hypotenuse.

24² = 7² + b² which solves for a positive value of b² so this is correct.

576 = 49 + b²

b² = 527

b = √527 ≈ 22.96 cm

Therefore, the length of the third side is approximately 22.96 cm.

Section 3: Advanced Applications

Problem 7: A ramp is built to reach a platform 2 meters high. The ramp is 5 meters long. How far away from the base of the platform does the ramp start?

Solution:

The ramp, the platform's height, and the horizontal distance from the base of the platform to the ramp's starting point form a right-angled triangle.

a = distance from base of the platform b = 2 meters c = 5 meters

Using the Pythagorean Theorem: a² + b² = c²

a² + 2² = 5²

a² + 4 = 25

a² = 21

a = √21 ≈ 4.58 meters

Therefore, the ramp starts approximately 4.58 meters away from the base of the platform.

Problem 8: A square has a diagonal of 10√2 cm. What is the length of each side?

Solution:

The diagonal of a square divides it into two congruent right-angled triangles. The diagonal is the hypotenuse, and the two sides of the square are the legs.

Let 'a' be the length of each side.

a² + a² = (10√2)²

2a² = 200

a² = 100

a = √100 = 10 cm

Therefore, the length of each side of the square is 10 cm.

Problem 9: A triangle has sides of length 5, 12, and 13. Is it a right-angled triangle? Justify your answer.

Solution:

If it's a right-angled triangle, the Pythagorean Theorem should hold true. The longest side (13) is the potential hypotenuse.

5² + 12² = 25 + 144 = 169

13² = 169

Since 5² + 12² = 13², the Pythagorean Theorem holds true. Therefore, this is a right-angled triangle.

Further Exploration and Applications

The Pythagorean Theorem extends far beyond basic geometric problems. It's essential in:

• Navigation: Calculating distances and bearings.
• Surveying: Determining distances and heights indirectly.
• Construction: Ensuring accurate measurements and building structures.
• Computer graphics: Creating and manipulating images.
• Physics: Calculating distances, velocities, and forces in various scenarios.

Understanding and applying the Pythagorean Theorem is a fundamental skill that opens doors to a deeper comprehension of mathematics and its real-world applications.

Frequently Asked Questions (FAQs)

Q1: Can the Pythagorean Theorem be used for triangles that are not right-angled?

A1: No. The Pythagorean Theorem only applies to right-angled triangles. For other types of triangles, different trigonometric formulas are needed.

Q2: What if I get a negative number when solving for a side length?

A2: A negative number indicates an error in the calculation or the initial assumptions about the triangle's side lengths. Lengths cannot be negative. Double-check your work and ensure the longest side is correctly identified as the hypotenuse.

Q3: Are there any real-world examples beyond those mentioned in the worksheet?

A3: Yes! Think about the diagonal bracing used in construction to strengthen structures, or the distance a bird flies to its nest from a point on the ground. Many everyday scenarios can be modeled using right-angled triangles and the Pythagorean Theorem.

Q4: How can I improve my understanding of the Pythagorean Theorem?

A4: Practice is key! Solve numerous problems of varying difficulty. Visualize the theorem using diagrams and consider real-world examples to make the concepts more tangible.

Conclusion

The Pythagorean Theorem, though seemingly simple, is a powerful tool with wide-ranging applications. This worksheet has provided a foundation for understanding and applying this critical theorem. Remember to practice regularly, explore its applications in different contexts, and continue to develop your mathematical problem-solving skills. By mastering the Pythagorean Theorem, you’ll be well-equipped to tackle more advanced mathematical concepts and real-world challenges. Keep practicing, and you'll become a Pythagorean Theorem expert in no time!