Equations in sentences?

Question

Some simple mathematic equations are converted into these sentences. What are they?

1. Candice's land (in $m^2$) is equal to the total area of Albert's land and Betty's land (in $m^2$).
2. On March 14$^{th}$, the frequency of the radiation waves is exponentially higher.
3. The price of a litre of water and cement squared is equal to ice, brick and two watery cement(s).
4. A number of power of a smaller number is derived from a power of number.
5. Signs over a reason is always temporary.

Answer 1

Complete answer changed again:

Candice's land (in $m^2$) is equal to the total area of Albert's land and Betty's land (in $m^2$).

1) $c^2=a^2+b^2$ Pythagoras' theorem.

On March 14th, the frequency of the radiation waves is exponentially higher.

2) Volume of a cylinder $V=(πr^2)h$

The price of a litre of water and cement squared is equal to ice, brick and two watery cement(s).

3) $(a+b)^2=a^2+b^2+2ab$

A number of power of a smaller number is derived from a power of number.

4) if $y=kx^n$ then $dy/dx=nkx^{n-1}$

Signs over a reason is always temporary.

5) $\tan θ = \sin θ/\cos θ$

Answer 2

March 14 could be written 314 which might be $\pi$ , that plus exponential could relate to Euler's equation