You will need. 1- to fit the rectangle tile in
Triangle-A is not "unique".
All of its angles are equal (60° each), and all of its sides
have the same length, but that length can be anything ...
1 millimeter, 1 light-year ... anything.
Each of the other choices can only be 1 triangle.
For each one, we can find the size of every angle,
and we can also find the length of every side.
Das is difference of 2 perfect squares
remember
a^2-b^2=(a-b)(a+b)
so
25x^4=(5x^2)^2
16y^2=(4y^2)
(5x^2)^2-(4y)^2=(5x^2-4y)(5x+4y)
cannot be factored further
224million is the correct answer.
7/10 of 320,000,000 is 224,000,000