You seem excited, it was just a question. With that said your logic is "the passengers for flight 77 are missing, therefore the pentagon must have been hit by that flight...." ?
The lack of debris, airplane parts and the size of the hole generate huge doubts in my mind. Several other things do as well.
If you believe the US government is beyond killing civilians for "national security", please open your eyes.
They found aircraft debris around the area. Not to mention there were plenty of eye witness accounts who saw the plane fly into the pentagon. There are 911 calls that confirm this.
Check out how low this plane is flying. It's obvious that the planes flown on 9/11 would have these same capabilities.
[ame="http://www.youtube.com/watch?v=0nBaU0vwP-o"]Proof Pentagon 9/11 planes can fly low and fast - YouTube[/ame]

You can clearly see an American Airlines debris

Same fuel explosions...
Many eyewitness accounts...
Steve Anderson:
Shortly after watching the second tragedy, I heard jet engines pass our building, which, being so close to the airport is very common. But I thought the airport was closed. I figured it was a plane coming in for landing. A few moments later, as I was looking down at my desk, the plane caught my eye. It didn't register at first. I thought to myself that I couldn't believe the pilot was flying so low. Then it dawned on me what was about to happen. I watched in horror as the plane flew at treetop level, banked slightly to the left, drug it's wing along the ground and slammed into the west wall of the Pentagon exploding into a giant orange fireball. Then black smoke. Then white smoke.
Paul Begala:
Paul Begala, a Democratic consultant, said he witnessed an explosion near the Pentagon. "It was a huge fireball, a huge, orange fireball," he said in an interview on his mobile phone.
Brian Birdwell:
LTC Brian Birdwell. He was just heading back down the hall to his office when the building exploded in front of him. ... Once they stabilized Brian, they transferred him to George Washington Hospital where...the best, cutting edge burn doctor in the U.S. The doctor told him that had he not gone to Georgetown first, he probably would not have survived because of the jet fuel in his lungs.
Sean Boger:
Sean Boger, Air Traffic Controller and Pentagon tower chief - "I just looked up and I saw the big nose and the wings of the aircraft coming right at us and I just watched it hit the building." "It exploded. I fell to the ground and covered my head. I could actually hear the metal going through the building."
Mark Bright:
"I saw the plane at the Navy Annex area," he said. "I knew it was going to strike the building because it was very, very low -- at the height of the street lights. It knocked a couple down." The plane would have been seconds from impact -- the annex is only a few hundred yards from the Pentagon. He said he heard the plane "power-up" just before it struck the Pentagon. "
Omar Campo:
It was a passenger plane. I think an American Airways plane, Mr Campo said. "I was cutting the grass and it came in screaming over my head. I felt the impact. The whole ground shook and the whole area was full of fire."
Allen Cleveland:
Allen Cleveland of Woodbridge Virginia looked out from a Metro train going to National Airport, to see a jet heading down toward the Pentagon. "I thought, 'There's no landing strip on that side of the subway tracks,' " Before he could process that thought, he saw "a huge mushroom cloud. The lady next to me was in absolute hysterics."" . . a silver pasenger jet, mid sized"
Dan Creed:
He and two colleagues from Oracle software were stopped in a car near the Naval Annex, next to the Pentagon, when they saw the plane dive down and level off. "It was no more than 30 feet off the ground, and it was screaming. It was just screaming. It was nothing more than a guided missile at that point," Creed said. "I can still see the plane. I can still see it right now. It's just the most frightening thing in the world, going full speed, going full throttle, its wheels up," Creed recalls.
Wayne Day:
"We had one guy who was standing, looking out the window and saw the plane when it was coming in. He was in front of one of the blast-resistant windows," says Kirlin President Wayne T. Day, who believes the window structure saved the man's life. According to Matt Hahr, Kirlin's senior project manager at the Pentagon, the employee "was thrown about 80 ft down the hall through the air. As he was traveling through the air, he says the ceiling was coming down from the concussion. He got thrown into a closet, the door slammed shut and the fireball went past him," recounts Hahr. "Jet fuel was on him and it irritated his eyes, but he didn't get burned."
Michael DiPaula:
"Suddenly, an airplane roared into view, nearly shearing the roof off the trailer before slamming into the E ring. 'It sounded like a missile,' DiPaula recalls . . . Buried in debris and covered with airplane fuel, he was briefly listed by authorities as missing, but eventually crawled from the flaming debris and the shroud of black smoke unscathed.
Steve Eiden:
Steve Eiden, a truck driver, had picked up his cargo that Tuesday morning in Williamsburg, Va., and was en route to New York City and witnessed the aftermath. He took the Highway 95 loop in the area of the Pentagon and thought it odd to see a plane in restricted airspace, thinking to himself it was odd that it was flying so low. "You could almost see the people in the windows," he said as he watched the plane disappear behind a line of trees, followed by a tall plume of black smoke. Then he saw the Pentagon on fire, and an announcement came over the radio that the Pentagon had been hit.
Penny Elgas:
The plane seemed to be floating as if it were a paper glider and I watched in horror as it gently rocked and slowly glided straight into the Pentagon. At the point where the fuselage hit the wall, it seemed to simply melt into the building. I saw a smoke ring surround the fuselage as it made contact with the wall. It appeared as a smoke ring that encircled the fuselage at the point of contact and it seemed to be several feet thick. I later realized that it was probably the rubble of churning bits of the plane and concrete. The churning smoke ring started at the top of the fuselage and simultaneously wrapped down both the right and left sides of the fuselage to the underside, where the coiling rings crossed over each other and then coiled back up to the top. Then it started over again -- only this next time, I also saw fire, glowing fire in the smoke ring. At that point, the wings disappeared into the Pentagon. And then I saw an explosion and watched the tail of the plane slip into the building.
Afework Hagos:
Afework Hagos, a computer programmer, was on his way to work but stuck in a traffic jam near the Pentagon when the plane flew over. "There was a huge screaming noise and I got out of the car as the plane came over. Everybody was running away in different directions. It was tilting its wings up and down like it was trying to balance. It hit some lampposts on the way in."
Albert Hemphill:
All in all, I probably only had the aircraft in my field of view for approximately 3 seconds. The aircraft was at a sharp downward angle of attack, on a direct course for the Pentagon. It was "clean", in as much as, there were no flaps applied and no apparent landing gear deployed. He was slightly left wing down as he appeared in my line of sight, as if he'd just "jinked" to avoid something. As he crossed Route 110 he appeared to level his wings, making a slight right wing slow adjustment as he impacted low on the Westside of the building to the right of the helo, tower and fire vehicle around corridor 5.
Nicholas Holland:
Nicholas Holland, an engineer with AMEC Construction Management of Bethesda, Md., had spent the last two years working to reinforce the walls. Two summers ago, a blast wall of reinforced steel and concrete was installed right where the plane hit.