What is the classification of a triangle with side lengths of 10, 10, and 9?

A. Obtuse

B. Acute

C. Right

B. Acute triangle

You have to square all three numbers which would be 100, 100, and 81. The next step is adding the two shortest sides, which would be 100 & 81. The sum of those two sides add up to 181. If the sum is greater than the 3rd side squared than it would be acute. If the sum and the third side squared were equal it would be a right triangle. If the 3rd side squared was greater than the sum of the two sides squared it would be obtuse