Atriangle has a side lengths of 18cm, 80 cm and 81cm. classify it as acute obtuse or right?

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.

65

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whatvare the choices

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