Answer:
1.)

2.)

3.)

4.)

5.)

6.)

7.)

Explanation:
Use the 45°-45°-90° formula:

1.) Insert values:

Simplify:

2.) In a 45°-45°-90° angle, the legs have the same value.

3.) x is the hypotenuse. Insert values:

Simplify:

4.) Insert values:

Divide
from both sides:

Rationalize the left side:

Simplify:

5.) Insert values:

Divide
from both sides and rationalize:


Simplify:

6.) 10 is the hypotenuse. Insert values:

Divide
from both sides and rationalize:


Simplify:

7.) Draw the figure like the squares in problems 3 and 10. The problem says that the perimeter is 48, so divide 48 by 4, which is 12. A side is 12 meters (or a leg). The diagonal is the hypotenuse of a triangle. Insert values:

Simplify:

Finito.