Answer:
64 and 81
Step-by-step explanation:
Area is base x height
8cm is the base , 8 cm is the height
8x8=64cm
Answer:
8.06
Step-by-step explanation:
Use the Pythagorean theorem:

The hypotenuse is always the slanted side, or c (x in this picture), but the other numbers can be interchanged. Doesn't matter.
Plug the numbers 4 and 7 into the formula.

Now evaluate them to get 
16+49=65
To get c, take the square root of 65

To calculate the speed, divide 15.75 by 2.25 and you get 7 mph.