The radius of the base of the cylinder is 1, the height is 20. The sectional area parallel to the axis is 20 kV units.

The radius of the base of the cylinder is 1, the height is 20. The sectional area parallel to the axis is 20 kV units. At what distance from the axis is the sectional area?

The AВСD section is a rectangle with an area of 20 cm2.

Ssection = 20 = AB * BC = 20 * BC.

BC = 20/20 = 1 cm.

Let’s construct the radii of the circle OB and OС at the base of the cone.

In the triangle OB = OС = R = 1 cm, BC = 1 cm, then the ВOС triangle is equilateral.

Since the BOS triangle is equilateral, all its angles are equal to 60.

Then Svos = OB * OС * Sin30 / 2 = 1 * 1 * √3 / 4 cm2.

Also Svos = BC * OH / 2.

OH = 2 * Svos / BC = (2 * √3 / 4) / 1 = √3 / 2 cm.

Answer: The section is at a distance of √3 / 2 cm from the axis of the cylinder.