Confused on this work

We know that :
⊕ Sum of the interior angles in a Pentagon should be equal to 540°
⇒ x° + (2x)° + (2x)° + 90° + 90° = 540°
⇒ (5x)° = 540° - 180°
⇒ (5x)° = 360°
[tex]\sf{\implies x^{\circ} = \dfrac{360^{\circ}}{5}}[/tex]
⇒ x° = 72°