Find the third angle of a triangle
The three angles of a triangle add up to 180 degrees.
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
Two angles of a triangle are 18° and 21°. How many degrees is the third angle?
Answer: 141
Two angles of a triangle are 48° and 21°. How many degrees is the third angle?
Answer: 111
Two angles of a triangle are 66° and 89°. How many degrees is the third angle?
Answer: 25
Tip: The three angles of a triangle add up to 180 degrees.
Print a worksheet of this skill New questions and an answer key, free.
Up next
- Next in this topic Acute angles in a right triangle Grade 7
- Ready for more Corresponding angles and parallel lines Grade 8
Print a free worksheet with answers (20 questions).
Practice without limits
Members practice as much as they like, every day, and get the printable packs and lessons too.