is the same thing here as the other triangles, the triangle below is an equilateral, the one above is an isosceles.
the <u>vertex</u> of the isosceles is 40°, so the twins angle at the <u>base</u> are (180 - 40)/2 = 70° = x each.
since the sides in the equilateral are all the same length, then 2y + 10 = x - y, but we already know what "x" is, so

Answer is C as all other choices are even numbers therefore make the equation non-integer.
The lengths of two sides is not enough information to determine a unique triangle. There are an infinite number of possible correct answers. If 'x' is the length of the third side, then its length can be anything between 3 and 13.
So the equation is A = P(1+rt)
A = 10,000(1+0.07*6)
A = 10,000(1+0.42)
A = 14,200.00