Answer:
It would be an obtuse scalene triangle.
EDITED TO ADD:
When given 3 triangle sides, to determine if the triangle is acute, right or obtuse:
1) Square all 3 sides.
2) Sum the squares of the 2 shortest sides.
3) Compare this sum to the square of the 3rd side.
if sum > 3rd side² Acute Triangle
if sum = 3rd side² Right Triangle
if sum < 3rd side² Obtuse Triangle
6^2 = 36
10^2 = 100
12^2=144
36 + 100 = 136 and this is less than 144 so it is an obtuse triangle.
Explanation: