These are photos of Hank the Wire Fox Terrier doing several of the most common obstacles on an Agility course.
This photo shows Hank coming down the A Frame. The dog goes up one side and down the other side. See the yellow at the lower part of the A Frame? That is a contact point and the dog must touch that on each side. He cannot jump off the A Frame above the contact points. The A Frame has 9′ sides and a 5′ to 6′ spread at the bottom for fox terriers.
This is the pause table. The dog must jump up on the table and under the command of the handler either sit, down or stand on the table and hold it for 5 seconds before moving on. The height of the table depends on the height of the dog.