Please help me solve the question.

Find the total area for the regular pyramid ( follow the answer set up in the picture)

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.

The moats separating people from the animals are 5 m wide for lions and 4 m wide for the elephants. if the lion’s moat is 4 m deep, how deep should the elephants’ moat be?