Derivada de x al cuadrado

1-for what value of x is line a parallel to line b 2-for what value of x is line a parallel to line b

In the diagram below, abc is congruent to dec what is the value of x

The perimeter of an equilateral triangle is 4 cm more than the perimeter of a square and the length of a side of the triangle is 8 cm more than the length of a side of the aware. find the length of a side of the equilateral triangle