Mathematics
Grade 8
15 min
Pythagorean theorem: word problems
Pythagorean theorem: word problems
Tutorial Preview
1
Introduction & Learning Objectives
Learning Objectives
Identify right triangles within real-world word problem scenarios.
Distinguish between the legs and the hypotenuse in a word problem context.
Translate real-world scenarios into mathematical models using the Pythagorean theorem.
Solve word problems involving finding the length of a missing side of a right triangle.
Interpret the numerical solution in the context of the original word problem.
Draw accurate diagrams to represent word problems involving right triangles.
Ever wondered how construction workers know the exact length of a diagonal brace for a wall, or how far you'd walk if you cut across a rectangular park? πΆββοΈπ
In this lesson, you'll learn how to apply the powerful Pythagorean theorem to solve real-world problems. We'll pract...
2
Key Concepts & Vocabulary
TermDefinitionExample
Right TriangleA triangle that has one angle measuring exactly 90 degrees.A corner of a square room forms a 90-degree angle, so a diagonal line across the room would create two right triangles.
Legs (of a right triangle)The two sides of a right triangle that form the 90-degree angle. These are typically represented by 'a' and 'b' in the Pythagorean theorem.In a ladder problem, the height the ladder reaches on the wall and the distance the base of the ladder is from the wall are the legs.
HypotenuseThe side opposite the right angle in a right triangle. It is always the longest side and is represented by 'c' in the Pythagorean theorem.The ladder itself, leaning against a wall, represents the hypotenuse.
Word ProblemA mathematical problem pr...
3
Core Formulas
Pythagorean Theorem
$a^2 + b^2 = c^2$
This fundamental theorem states that in any right triangle, the square of the length of the hypotenuse (c) is equal to the sum of the squares of the lengths of the two legs (a and b). It is used to find the length of an unknown side when the other two sides are known.
Identifying Sides in Word Problems
In a right triangle formed by a word problem, the longest side or the side representing a diagonal path is typically the hypotenuse (c). The two sides forming the right angle are the legs (a and b).
Before applying the Pythagorean theorem, it's crucial to correctly identify which parts of the word problem correspond to the legs and which corresponds to the hypotenuse. Often, a right angle is formed by perpendicular directions (e.g., N...
5 more steps in this tutorial
Sign up free to access the complete tutorial with worked examples and practice.
Sign Up Free to ContinueSample Practice Questions
Challenging
A ship sails 9 miles south and then 40 miles east. It then sails directly back to its starting point. What is the total distance the ship sailed?
A.49 miles
B.90 miles
C.81 miles
D.41 miles
Challenging
You have a piece of wood that is 3.5 feet long. You need to pass it through a doorway that is 3 feet tall and 1.5 feet wide. Will the piece of wood fit through the doorway diagonally?
A.Yes, because the diagonal is approximately 3.35 feet.
B.No, because the diagonal is approximately 3.35 feet.
C.Yes, because the diagonal is approximately 3.7 feet.
D.No, because the diagonal is approximately 3.7 feet.
Challenging
A right triangle is drawn on a coordinate plane with vertices at (1, 2), (1, 10), and (7, 2). What is the length of the hypotenuse?
A.10
B.14
C.8
D.6
Want to practice and check your answers?
Sign up to access all questions with instant feedback, explanations, and progress tracking.
Start Practicing Free