The Pythagorean Theorem unit pack (Grade 8 · CCSS 8.G.B.6, 8.G.B.7): every worksheet and exit ticket for this unit, ready to print in one go. The answer keys print at the end, each on its own page, so you can leave them off. To make a PDF, click Print and choose "Save as PDF." Games: Pythagorean Platforms
The Pythagorean Theorem
Grade 8 · CCSS 8.G.B.6, 8.G.B.7 · Pairs with the Pythagorean Platforms game
Name
Date
In a right triangle, a² + b² = c².
Legs a and b make the right angle. The hypotenuse c is across from it, and it's always the longest side.
Steps: plug in → square → add (or subtract) → take the square root.
Key vocabulary
right triangle: a triangle with one right angle
legs (a and b): the two sides that form the right angle
hypotenuse (c): the longest side, across from the right angle
Pythagorean theorem: in a right triangle, a² + b² = c²
square root (√): the number that, times itself, gives the original number: √25 = 5
Part A: Find the hypotenuse (the rope)
1.a = 6 ft, b = 8 ft. Find c.
c = ft
2.a = 5 ft, b = 12 ft. Find c.
c = ft
3.a = 12 ft, b = 9 ft. Find c.
c = ft
4.a = 15 ft, b = 8 ft. Find c.
c = ft
Part B: Find the missing leg (the distance to the next platform)
9. An explorer's vine is tied to a branch 12 ft above her platform. The next platform is 16 ft straight across. How long must the vine be to reach it? Draw the triangle.
Answer: ft
10. A 15 ft rope hangs from an anchor 9 ft above a platform. How far across can the explorer swing to the next platform?
Answer: ft
11. A 13 ft ladder leans against a wall. Its base is 5 ft from the wall. How high up the wall does it reach?
Answer: ft
12.Find the mistake. Jordan found the hypotenuse of a triangle with legs 6 and 8 like this: c = 6 + 8 = 14. What did Jordan do wrong? Find the correct answer.
2. A 10 ft ladder leans on a wall with its base 6 ft out. How high does it reach?
ft
3. Is a triangle with sides 7, 24 and 25 a right triangle? Show how you know.
Yes / No
Answer Key: The Pythagorean Theorem
For the teacher
6² + 8² = 36 + 64 = 100, √100 → c = 10 ft
5² + 12² = 25 + 144 = 169, √169 → c = 13 ft
12² + 9² = 144 + 81 = 225, √225 → c = 15 ft
15² + 8² = 225 + 64 = 289, √289 → c = 17 ft
a² + 6² = 10², a² = 100 − 36 = 64 → a = 8 ft
a² + 5² = 13², a² = 169 − 25 = 144 → a = 12 ft
15² + b² = 17², b² = 289 − 225 = 64 → b = 8 ft
24² + b² = 25², b² = 625 − 576 = 49 → b = 7 ft
Legs 12 and 16: 144 + 256 = 400, √400 → 20 ft
Hypotenuse 15, leg 9: 225 − 81 = 144, √144 → 12 ft
Hypotenuse 13, leg 5: 169 − 25 = 144, √144 → 12 ft
Jordan added the side lengths instead of their squares. Correct: 6² + 8² = 100, √100 → c = 10. (14 can't be right: the hypotenuse has to be shorter than the two legs added together.)
Common mistakes to watch for: adding the sides (#12), doubling instead of squaring (6² = 12), stopping at c² without taking the square root, and adding instead of subtracting when finding a leg (Part B). The game's wrong answer choices are built from these same mistakes.