Worksheets · Geometry

Similar right triangles worksheet

Dropping the altitude onto the hypotenuse makes two smaller triangles, both the same shape as the original. Matching up their sides is where the geometric mean comes from.

Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep

Sigma Prep · sigmaprep.io/worksheets

Name

Similar Right Triangles

Date Period

Find each length.

  1. Find the altitude1121x
  2. Find the altitude1211x
  3. Find the altitude624x
  4. Find the altitude1001x
  5. Find the altitude181x
  6. Find the altitude1100x
  7. Find the altitude254x
  8. Find the altitude250x
  9. Find the altitude348x
  10. Find the altitude1441x
  11. Find the altitude273x
  12. Find the altitude327x
  13. Find the altitude425x
  14. Find the altitude811x
  15. Find the altitude722x
  16. Find the altitude246x
  17. Find the altitude272x
  18. Find the altitude483x
  19. Find the altitude502x
  20. Find the altitude364x

Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep

Sigma Prep · sigmaprep.io/worksheets

Name

Similar Right TrianglesAnswer keyVersion 1

Date Period

Find each length.

  1. Find the altitude1121x11
  2. Find the altitude1211x11
  3. Find the altitude624x12
  4. Find the altitude1001x10
  5. Find the altitude181x9
  6. Find the altitude1100x10
  7. Find the altitude254x10
  8. Find the altitude250x10
  9. Find the altitude348x12
  10. Find the altitude1441x12
  11. Find the altitude273x9
  12. Find the altitude327x9
  13. Find the altitude425x10
  14. Find the altitude811x9
  15. Find the altitude722x12
  16. Find the altitude246x12
  17. Find the altitude272x12
  18. Find the altitude483x12
  19. Find the altitude502x10
  20. Find the altitude364x12

Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep

How to do these

The altitude splits the hypotenuse into 4 and 9

  1. The altitude is the geometric mean.
  2. Multiply the two pieces: 36.
  3. Take the square root.

The answer is 6.

Where students go wrong

Averaging the two pieces instead of multiplying them. The geometric mean is a square root of a product, and the ordinary average gives a different, wrong number every time the pieces differ.

Also called geometric mean, altitude to the hypotenuse or mean proportional.

Questions about these worksheets

Yes. Every similar right triangles sheet is free to print and free to download as a PDF. There is no account to make, no email to hand over and no limit on how many you take.

Yes. The answer key prints on a second page, and you can choose whether it shows each question beside its answer or just the answers in a list.

Yes. Print straight from the page, or download the PDF and print that. The sheet is laid out for paper rather than squeezed off a screen, so there is room to work under each question, and the answer key comes out on its own page.

Geometry is usually taken around 9th or 10th grade, though schools vary and plenty of students meet it earlier or later. Pick the difficulty rather than the grade: the easy level suits a first lesson on it, the hard level suits review before a test.

Yes, as many as you like. The questions are built fresh each time rather than picked from a fixed set of files, so pressing Generate gives a new sheet. That is what you want for a second class, a retake, or two students sitting next to each other.

That is the closest comparison, and Kuta Software is good software. It is also paid software you install on a computer. These worksheets run in a browser tab for free, with no account and nothing to install. Like Kuta, the similar right triangles questions are generated when you ask for them rather than pulled from a fixed set of files, so two classes never get the same sheet, and the answer key comes with it.

Yes. There are three levels, and you can tick more than one for a sheet that mixes them, in which case the questions come out easiest first. The harder levels are not just larger numbers: they ask for something the easy ones do not.

Averaging the two pieces instead of multiplying them. The geometric mean is a square root of a product, and the ordinary average gives a different, wrong number every time the pieces differ.