Hate to go contrary to the line of thought made above. But Triforce has already been proven to be a broken item. Search it up on the LoL forums. People have done calculations comparing Triforce to Infinity Edge and other B.F. Sword variants. Triforce loses to Infinity Edge in all areas of dps, since Infinity Edge boosts AD, which Riven actually needs, rather than some passive proc that doesn't help Riven's abilities as much. With Infinity Edge being both cheaper and more effective than Triforce, there's no reason for you to have it in your build.

That being said, your entire item list is made up wrong. Riven not being a huge, sustained auto-attacker, Doran's Blade isn't so good for her early-game as is Doran's Shield, which gives her hp regen, helping to keep her in the field longer, which is the point of Doran items anyways. Merc Treads are probably the best choice on this build, but not my personal choice. Riven benefiting hugely from Cooldown Reduction, I'd at least consider the merits of Ionian Boots, which are just about as good as Merc Treads.

Bloodthirster, I've always been on the hedge about. Sure, at full charges, it gives you more than your money's worth, which is always an amazing thing. The problem? Riven dies too much with defensive items, and isn't that great without defensive items. Dying resets your Bloodthirster's stacks, which keeps it from realizing its full potential. While I wouldn't recommend taking it off this list, I'd at least put it off till last, and sub in Infinity Edge instead, which gives you the AD you need sooner.

Guardian Angel is just a baaad item for Riven. I've seen it many times on enemy Rivens, and not once can I say it ever helped them. Riven being the squishy melee character she is, you're most likely to activate Guardian Angel in the middle of a fight, where your revival will be blocked by a couple Angel-sitters who will most likely smack you dead again the moment you've revived. Not the best item for Riven, since it's too expensive for something that just lets you get killed twice.

Force of Nature is a good item, if you want to go defensive. Infinity Edge, like I said before, should come sooner.

Now, some items that are missing that EVERY Riven build should at least strongly consider before passing up. Youmuu's Ghostblade has been a stalwart item on Riven builds since her inception. AD, CDR, Armor Pen, and an Active that helps you? Yes please! Take a look at the Ghostblade, and see if you need it or not.

But even more critical than the Ghostblade is Frozen Mallet. 700 hp!?!?!? 20 AD!?!?!? And a passive that slows enemies on auto-attacks? Even if Riven isn't an auto-attacker, you can still valor in towards someone, auto them to use up your Runic Blade's charge, then punish them with Ki Burst and Broken Wings and what have you. Seriously, I'm surprised that you passed up such a great item without even mentioning it in your guide.

Which leads me to the rest of your guide. Forgive me for being harsh here. The "Table of Contents" you creatively made is useless. You already have one, and the second one doesn't do anything for the reader. Spelling is a huge issue with this guide. learn to spell "Vampiric Scepter" before you include it in your guide. If you're not sure, you can find the item's name up top anyways. And I love the first Tip to playing with Riven. "Try to avoid Ranged". Yeah, right. Like it's that easy in playing any game with ranged characters in it. Avoiding ranged is like trying to avoid going to the bathroom.

All in all, you've got a lot to work on here.

agreed changes will be made

His Riven build is perfectly fine in normal games(tried it)
But in ranked, I really really cannot see SotA as a potential item in ranked. It's high risk high reward. So, I would rush a Bloodthirster followed by a Triforce or a defensive item (which your build does nt have)
At this rate, u might ad well call this guide "Glass Cannon 101 ;D" no offense