ANSWER
45.6cm to the nearest tenth.
Step-by-step explanation
The diagonal of the rectangular painting is 62cm.
The height of the painting is 42 cm.
The height of the painting h , the diagonal, and the width of the painting forms a right triangle with the diagonal being the hypotenuse.
From the Pythagoras Theorem,





The width of the painting is 45.6cm to the nearest tenth.