What is the perimeter of rectangle with sides 12cm and 8cm

Anyone? 15m is what percent of 60m; 3m; 30m; 1.5 km?

What is the value of the expression i 0 × i 1 × i 2 × i 3 × i 4? 1 –1 i –i

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.