Answer:

Explanation:
We are given a quadrilateral. It will be difficult to find x using this shape, but we can drop a perpendicular line and create a right triangle (refer to the attached image).
Match up the other sides. The height is equal to 4.
At the base, the longer portion is 7 because the line segment above the base is 7. Since the entire base is 10, the smaller portion must be 3 because 10-7=3.
Now we have 2 sides of a right triangle and one unknown. We can use the Pythagorean Theorem.

Where a and b are the legs and c is the hypotenuse.
In this triangle, 4 and 3 are the legs because they make the right angle. x is the hypotenuse because it is opposite the right angle.
Substitute the values into the formula.

Solve the exponents.



Take the square root of both sides of the equation to isolate the variable.


x is equal to 5.