Respuesta :
Answer:
Step-by-step explanation: 1st you are going to have to see...if it less than 90 it it is acute, if its directly at 90 it would be right...or, if the # is greater rhan 90 its obtuse, so if it is 18,80, and 81 what would it be remember...DO NOT ADD
Answer:
It is acute.
Step-by-step explanation:
81^2 = 6561
80^2 = 6400
18^2 = 324
80^2 + 18^2 = 6724
So 81^2 < 80^2 + 18^2 , therefore the triangle is acute.
NOTE: In a triangle with sides a, b and c with a = longest side,
if a^2 < b^2 + c^2 the triangle is acute. In a right angled triangle a^2 = b^2 + c^2. In an obtuse angled triangle a^2 > b^2 + c^2.