You will learn the track of using the properties of similar traingles of find the length (ooposite side) of the upper left triangle. This helps us to find the value of the length of the hypotenuse of the same but the larger triangle usng Pythagora´s theorem. This length when found is the side length of the square. You need to solve for the length of the diagonal of the square and having been given the smaller side length of the bottom square and knowing the adjacent angle , we use cosine rule to find the value of x.
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