Answer:
5. Obtuse
6. Right
7. Acute
Explanation:
5. 5,12,15
The square of the longest side is 15^2 = 225. The sum of the squares of the two shorter sides is 5^2 + 12^2 = 169. Since 169 < 225, the triangle is obtuse.
6. 6,8,10
The square of the longest side is 10^2 = 100. The sum of the squares of the two shorter sides is 6^2 + 8^2 = 100. Since 100 = 100, the triangle is right.
7. 12,10,13
The square of the longest side is 13^2 = 169. The sum of the squares of the two shorter sides is 12^2 + 10^2 = 244. Since 244 > 169, the triangle is acute.