Menkaure's Pyramid

  • Hi,
    I havereached about half way and just killed the scorpion attacking theguardin the building and picked up the keys.
    Cannot get across the pit on the left. Walthrougs say"Jump and grab sandy colored rock outcropping on right side.
    I have made Lara jump all over but always drops off .
    How can I find which rock is the right one to jump to and grab before shimmying left?