The fossil leg bone you see in the picture is actually not a real artifact. Nobody found it. It's a sculpture.
In fact, the information on the picture says that it's a sculpture and not a real human bone. Physically it's not thick enough to support a human
that would be that tall (well over 15 feet tall.) The height limit on human giants seems to be around 9 feet tall, and their systems are fragile (the
bones break easily for one thing.)
The other observation I'd like to make regards human reproduction and giants.
Now... I'm sure it's exciting and erotic to think of it, but if you've got someone with a male reproductive organ that's the size of your arm
and he's fully aroused and he wants to insert ALL of it in your body -- frankly, most normal sized people of that time would Run Away Very Quickly.
If he got rough, you wouldn't survive. If he's on top, he'd crush you or smother you -- IF he could achieve arousal.
So, if you were building a giant the bone proportions would have to be much different. For a good ecological example, take a look at the eohippus
("dawn horse") skeletons and then take a look at a modern horse skeleton. They're very different in size and structure and a modern quarterhorse
couldn't mate with little eohippus.
Same problem with the idea of human giants.
Ah yes. For a good example of the thickness needed for a 15-20 foot tall biped, take a look at the T-rex skeletons.
www.jpaftermath.com...
You'll find that all other bipedal dinos of the same height had leg bones of about the same thickness. That sculpted femur would never have stood
the weight.