Which of the following statement(s) about cyclohexane is/ are wrong?

Only the chair form is free from angle strain.

Stability of different conformations of cyclohexane is:
Chair > Boat > Twist boat > Half chair.

Half chair has five C atoms is one plane and one C atom out of the plane. Hence, it has both eclipsing and bond angle strains and is the least stable conformer of
cyclohexane.

Twisting the boat to the skew boat conformation moves the 'flagpole' H atoms away from each other and reduces the eclipsing strain. Hence, the twist boat is more stable than the boat conformation.