C. Obtuse
To determine if the triangle is acute, obtuse, or right, we can use the Pythagorean theorem. In a right triangle, the square of the length of the longest side is equal to the sum of the squares of the other two sides.
18^2 + 80^2 = 324 + 6400 = 6724
81^2 = 6561
Since 6724 > 6561, the triangle is obtuse.
A triangle has side lengths of 18cm, 80cm, and 81cm. Is the Triangle acute, obtuse, or right?
A. Right
B. Acute
C. Obtuse
1 answer