Question

roofing fai and max are building a new roof. they wanted a roof with two sloping planes that intersect in a curved arch. is this possible? such a roof is select choice because two select choice planes intersect in a straight line.

Explanation:

Step1: Recall plane intersection rule

Two planes intersect in a straight line (by the postulate of plane intersection: if two planes intersect, their intersection is a line).

Step2: Analyze the roof's arch

The roof has two sloping planes. If they intersect, it must be a straight line, not a curved arch. So such a roof is not possible. The second blank: the planes are "sloping" (which are flat planes, as roofs are made of flat surfaces). So two flat planes intersect in a straight line.

Answer:

First blank: not possible; Second blank: flat