Pls help Need help with plate tectonics

Which statement is a proper biconditional statement for the conditional statement: if a line intersects a line segment at its midpoint, then it is a segment bisector. if a line is a segment bisector, then it intersects the line segment at its midpoint. if a line does not intersect a line segment at its midpoint, then it is not a segment bisector. a line intersects a line segment at its midpoint if, and only if, it is a segment bisector. if a line is not a segment bisector, then it does not intersect the line segment at its midpoint.

Which measure of humidity, relative humidity or dew point, best describes the actual quantity of water vapor in a mass of air

The pyramid has a square base that us inscribed in the circular base of the cone. draw an image of the composite shape of the base. 2) if the side length of the square base is 8 units long, what is the diameter of the circular base of the cone from the picture in number 1