Answer:

Explanation:
Q5.
x it's a diagonal of a square.
The formula of a length of diagonal of a square:

a - side of a square
We have a = 45.
Substitute:

Q6.
Look at the first picture.
In a triangle 45° - 45° - 90°, all sides are in ratio 1 : 1 : √2.
In a triangle 30° - 60° - 90°, all sidea are in ratio 1 : √3 : 2.
Look at the second picture.
from the triangle 45° - 45° - 90°
multiply both sides by √√2 (use √a · √a = a)
divide both sides by 2

from the triangle 30° - 60° - 90°

