the walls of a room are representation of what basic element of geometry

The walls of a room represent the basic element of geometry called planes. Planes are two-dimensional surfaces that extend infinitely in all directions. In the case of a room, the walls form planes that enclose a three-dimensional space.

which of the following is the measure of an obtuse anle

a 40
b 100
c 90
d 180

The measure of an obtuse angle is greater than 90 degrees and less than 180 degrees. Therefore, the answer is (b) 100.

The walls of a room in basic geometry are usually represented by two-dimensional shapes called rectangles. A rectangle is a quadrilateral with four right angles and opposite sides that are equal in length.