1. ## The Distance Across

I think the dimensions of the rectangle are sqr(2a^2) and sqr(2b^2) if two ticks are b and one tick is a. IDK where to continue though

2. ## Re: The Distance Across

shaded area = $a^2+b^2 = 50 \, cm^2$

$|MK| = \sqrt{(a\sqrt{2})^2 + (b\sqrt{2})^2}$