Please please help Question 1: What is the diameter of the semi-circular cutout in the rectangle? *
2: What is the area of the figure? *
3: The figure represents a rug with a cutout to fit around a fireplace hearth. If the carpet costs $1.50 per square foot, how much will the rug cost? *

Really need on these. i have no idea what to do

Afamily has five members. a mom, a dad, two sisters, & a brother. the family lines up single file. what is the probabillity that the mom is at the front of the line

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.