Whenever a magnetic field linked to loop changes, the current is induced in the loop which sequentially opposes the cause of change in magnetic flux. So whenever the magnet moves towards and away from the loop then it causes the current to induce in the loop to oppose the change in magnetic flux by effectively creating a similar pole that is coming towards the loop.
For example, if the magnet north pole is coming towards loops then it effectively creates a north pole in front of the magnet.
Since the sum of the squares of the lengths of the two shorter sides is not equal to the square of the length of the longest side, the triangle is not a right triangle.
