Your notation is unclear, but I assume you mean a circle with center M and radius 4.
This is just a disguised way of asking about the Pythagorean theorem.
EMT is a right triangle with hypotenuse EM and legs ET and 4.
Since 3ET = EM, plug the values into the Pythagorean theorem and solve for ET.
T
Lebron J.
What’s the equation10/03/19