First write out your original equation.

Then use the law of exponents(power of a power) to simplify.

(Multiply the numerator and denominator exponents by the outside power.)
The answer is 4 to the 21st over 5 to the 6th.
Check the picture below
the angle is in degrees, thus, when taking the tangent, make sure your calculator is in Degree mode
Use the Pythagorean Theorem. a^2+ b^2=c^2.
In this case, it is c^2-b^2=a^2, so your answer is 4.686 mm^2. Round if you need to.
90+80+90+x=360
260+x=360
x=100
There is no upper limit so, so x is greater than or equal to 24 (x ≥ 24)