Too Tall Thomas has put Rodney’s book bag on the snack-shack roof. Rodney goes to borrow a ladder from the school custodian. The tallest ladder available is $10$ feet long and the roof is $9$ feet from the ground. Rodney places the ladder’s tip at the edge of the roof. The ladder is unsafe if the angle it makes with the ground is more than $60^\circ$. Is this a safe situation? Justify your conclusion.