Find the area and perimeter of all of these shapes?

Mindy bought 5/8 pound of almonds and a 3/4 pound of walnuts. which pair of fraction cannot be used to find how many pounds of nuts she bought in all.

If tan2a=cot(a+60), find the value of a, where 2a is an acute angle

Adolphin is swimming with her friend. the dolphin jumps to a height of 4.54.54, point, 5 meters above the surface of the water as her friend swims 9.89.89, point, 8 meters directly below her. what is the position of the dolphin's friend relative to the surface of the water? meters