Obtuse-angled triangle and Trilateral

Obtuse-angled triangle noun - A triangle that contains an obtuse interior angle.

Trilateral and obtuse-angled triangle are semantically related. In some cases you can use "Trilateral" instead a noun phrase "Obtuse-angled triangle".

Trilateral noun - A three-sided polygon.

Obtuse-angled triangle and trilateral are semantically related. Sometimes you can replace phrase "Obtuse-angled triangle" with "Trilateral", this terms are similar.