Use the Phythagorean Theorem, because bisecting a rectangle using the diagonal will produce 2 triangles. The diagonal represents the hypotenuse of the triangle so to solve for it you'd use the formula c² = a²+b²
To find x, we would have to find the hypotenuse of the 45-45-90 triangle. First, we would have to find the hypotenuse by using the 30-60-90 triangle on top to find it.
For a 30-60-90 triangle, the hypotenuse is 2x in length. the x is the same in all sides. All you would have to do is to plug it in. The leg opposite of 60° is x√3 in length. the leg opposite of 30° is x in length.
Since we know that 7 is opposite of the 30° angle, we know that x is 7. Across fron 60° is the hypotenuse of the 45-45-90 triangle. That leg is x√3. We plug in x=7 and get 7√3.
The hypotenuse of the 45-45-90 triangle is x√2 and the legs are both x. We can set 7√3 equal to x√2 to find x of the missing side.
