Answer:
x = 
Step-by-step explanation:
The altitude of the triangle must equal 4 because it is a right triangle with another leg of 3 and a hypotenuse of 5 (reason is due to the pythagorean theorem)
Therefore, the triangle on the right has legs of 4 and 7 and, again, use the phythagorean theorem to find 'x' (the hypotenuse)
+
= 
16 + 49 = 
65 = 
x = sq rt 65
X+ 4? idk I don't really understand the question...