A square pyramid has a base side length of 20. 4 cm and a height of 18. 2 cm. Which square pyramid is similar? base side length = 18. 2 cm, height = 20. 4 cm base side length = 22. 9 cm, height = 20. 7 cm base side length = 30. 6 cm, height = 27. 3 cm base side length = 40. 8 cm, height = 45. 5 cm.