Answer:
10.78 units
Step-by-step explanation:
Here as the composite figure has a rectangle and right angled triangle
The rectangle has opposite sides equal, as I drew.
For the right angled triangle 8-4 = 4 = adjacent side
10 = base
x = hypotenuse
By Pythagoras theorem
x² = 10²+4² = 100+16 = 116
x = √116 = 2√29 = 10.78 units
Answer: About 10.78 (square root of 116)
Step-by-step explanation: Because we have two right angles at the top, we know the lines of length 8 and 4 are parallel. Because of this, if we draw an imaginary line starting at the bottom of the line of length 4, and go straight across to touch the parallel line, we now have right triangle at the bottom of the picture. We know our imaginary line has a length of 10, because of the line at the top of the picture. We also know the section of our triangle that's made up of part of the line of length 8, has a length of 4 for our triangle. We know because we can subtract the value of the line of length four, because we started our imaginary line at the bottom of it. Next, it's just 10^2 + 4^2 = x^2 (Pythagorean Theorem). That gives us x^2= 116. X = 10.78 (approximate square root of 116).