Find a missing side of a right triangle
Use a² + b² = c² and solve for the missing leg: subtract the known leg squared from the hypotenuse squared.
Loading a question…
You've done today's 10 free questions.
Come back tomorrow for 10 more, or get unlimited practice with a membership.
Want more today? Print 20 more questions free, with the answers.
Already a member? Sign in.
See worked examples
A right triangle has legs of 80 km and 18 km. How long is the hypotenuse, in km?
Answer: 82
A right triangle has legs of 70 cm and 24 cm. How long is the hypotenuse, in cm?
Answer: 74
A right triangle has legs of 27 cm and 120 cm. How long is the hypotenuse, in cm?
Answer: 123
Tip: Use a² + b² = c² and solve for the missing leg: subtract the known leg squared from the hypotenuse squared.
Print a worksheet of this skill New questions and an answer key, free.
Up next
- Next in this topic Find the hypotenuse: round to the nearest tenth Class 8
Print a free worksheet with answers (20 questions).
Practise without limits
Members practise as much as they like, every day, and get the printable packs and lessons too.