A kite is a flat shape with straight sides. It has two pairs of equal-length adjacent (next to each other) sides.
Main properties of an arbitrary kite:
- Two pairs of sides are of equal length.
- One pair of diagonally opposite angles is equal.
- Only one diagonal is bisected by the other.
- The diagonals cross at 90°.
1. Option 1 is false, because sides that are adjacent to the right angle could have different lengths or diagonals can cross not at 90°.
2. Option 2 is correct, because this option is strictly the definition of the kite.
3. Option 3 is false, because MK and LJ can be not perpendicular, and then adjacent sides will not have the same lengths.
4. Option 4 is false, because despite the perpendicularity between MK and LJ, this figure could be rhombus (with all equal sides) or square (with all equal sides and all right angles).
By the way, rhombus and square are partial cases of kite, but in general, an arbitrary kite is not rhombus and is not square.
Answer: correct choice is 2.