Answer:
t = 6√3 mm
Step-by-step explanation:
The angles of the triangle are 30°, 60°, and 90°. That's lucky for you, because the sides of a 30°-60°-90° triangle are always in the ratio 1:√3:2
The side opposite the 90° angle is 12 mm, so the side opposite the 30° angle is 12/2 = 6 mm
t = side opposite the 60° angle = 6√3 mm.
