7. The diameter of the base of the cylinder was doubled and at the same time its height was halved. How did the area of the lateral surface and the volume of the cylinder change?
7. The length of the circumference of the base of the cylinder has doubled, and the height has been halved, so the lateral surface area remains unchanged. When the radius of the base is doubled, its area increases fourfold, and when the height is halved at the same time, the volume of the cylinder doubles.

![](https://cdn.mathpix.com/cropped/2024_05_21_5cdadc99c18e78f1502ag-178.jpg?height=463&width=616&top_left_y=1867&top_left_x=1094)

Fig. 108