the flagpole cast an 8 foot shadow, as shown in the table. At the same time the oak tree cast a 12 foot shadow. How tall is the oak tree? And the flagpole height is 20 ft

The flag pole is 20 feet tall with an 8 foot shadow.

The tree is X feet tall with a 12 foot shadow.

20/8 = X/12

Cross multiply:

20 * 12 / 8*X

240 = 8x

Divide both sides by 8:

x = 240/8

x = 30

The tree is 30 feet tall.