Grade 8 · Year 9 · Class 8 · ages 13–14 · Geometry
Pythagorean theorem: Grade 8 practice
Finding a side of a right-angled triangle using a² + b² = c². Eight questions at a time, instant feedback and a mastery score from 0 to 100.
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The idea in one minute
The hypotenuse is always the longest side, opposite the right angle. Square the sides, add them, then square root.
Try these on paper first
One question at each level. Tap a question to see the answer.
Easy A right triangle has legs of 5 and 12. The hypotenuse is
Answer: 13
Medium A right triangle has legs of 18 and 80. The hypotenuse is
Answer: 82
Challenge A right triangle has a hypotenuse of 87 and one leg of 60. The other leg is
Answer: 63
More ways to practise pythagorean theorem
- Printable pythagorean theorem worksheet with an answer key (new questions every time)
- Angle Estimator: Guess the size of an angle in degrees and see how close you were.
- The Pythagorean Theorem: an interactive lesson on the idea behind it
- All Grade 8 practice · Geometry worksheets
Related skills
- Volume of cylinders (Grade 8)
- Circles, circumference and area (Grade 7)
- Surface area of cuboids (Grade 7)
- Area of rectangles, triangles and parallelograms (Grade 6)
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FAQ
Pythagorean theorem: questions
What grade is pythagorean theorem?
It is usually taught in Grade 8 (Year 9 in England, Class 8 in India, ages 13–14), though schools and countries differ. Try the grade above or below if it feels too hard or too easy.
What does a pythagorean theorem question look like?
For example: "A right triangle has legs of 18 and 80. The hypotenuse is" The answer is 82. The hypotenuse is always the longest side, opposite the right angle. Square the sides, add them, then square root.
What should I learn before and after pythagorean theorem?
Before it, try surface area of cuboids (Grade 7). After it, move on to volume of cylinders (Grade 8).
How can I get better at pythagorean theorem?
The hypotenuse is always the longest side, opposite the right angle. Square the sides, add them, then square root. Practise a little every day, read the hint after each wrong answer, and use the printable worksheet when you want to write it out.
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