A square napkin is folded in half on the diagonal and placed on the diameter of a round

plate . If the folded napkin spans the plate and the plate has an 18-inch

diameter, what is the area of the space on the plate that is NOT covered by the napkin?

Leave your answer in terms of .

Prove that quadrilateral is a rhombus.

Aadc is formed by reflecting aabc across line segment ac, as shown in the figure. if the length of ac is 4 units, the area of aadc is square units.

Suppose you are choosing a 6-digit personal access code. this code is made up of 4 digits chosen from 1 to 9, followed by 2 letters chosen from a to z. any of these digits or letters can be repeated. find the total number of personal access codes that can be formed. 492,804 341,172 39,917,124 4,435,236