Pythagorean theorem worksheet for Geometry
Most of these triangles have whole-number sides from common triples, so the answers come out clean. The rest round to the nearest tenth, and the area questions find the missing leg first.
Also taught in Pre-Algebra, at its own level and with its own examples.
Not quite the one you need? Same words, different skill:
- Converse of the Pythagorean Theorem (Geometry). Right, acute or obtuse, from the three sides.
- The Diagonal of a Box (Geometry). Pythagoras twice: across the base, then up.
Select your difficulty
Pick more than one for a sheet that mixes them.
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Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep
Sigma Prep · sigmaprep.io/worksheets Name The Pythagorean Theorem Date Period Find each missing length or area. Leave square roots exact unless the question says to round.
Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep |
Sigma Prep · sigmaprep.io/worksheets Name The Pythagorean TheoremAnswer keyVersion 1 Date Period Find each missing length or area. Leave square roots exact unless the question says to round.
Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep |
How to do these
The legs of a right triangle are and . Find the hypotenuse
- Square both legs: 36 and 64.
- Add them: 100.
- Take the square root.
The answer is .
Where students go wrong
Using the theorem to find a leg by adding rather than subtracting. The hypotenuse squared is the total, so finding a leg means taking the other one away from it.
Also called Pythagoras, finding the hypotenuse or missing leg.
What you can put on this worksheet
- A missing side, left exact
- One leg of a right triangle is and its hypotenuse is . Find the other leg. →
- Problems that take two steps
- A rectangle has a diagonal of 39 and a side of 15. Find its perimeter. →
- Word problems
- A hiker walks 9 km north, then 40 km east. How far is the hiker from the start, in a straight line? → km
- Area from the hypotenuse and a leg
- Find the area. — a right triangle, labeled 130, 66 →
- Decimal sides, rounded
- Find the missing side to the nearest tenth. — a right triangle, labeled x, 7.8, 2.6 →
- Split by the altitude: the other piece, or the area
- Find . — a triangle split by its altitude, labeled 37, 15, 9, x →