Consider triangle MOP. This triangle is right triangle, because m∠P=90°.
Since m∠P=90°, m∠M=60°, then m∠O=180°-90°-60°=30°.
The leg opposite to the angle with measure 30° is half of the hypotenuse. Let the leg MP=x, then the hypotenuse MO=2x. By the Pythagorean theorem,

The perimeter of triangle MOP is

Since
then

Answer: MP=4 units.