A shelf holds 12 books in a row. How many ways are there to choose five books so that no two adjacent books are chosen

792 ways

Step-by-step explanation:

We can solve this using the combination formular

where n represents the total number of objects/items, and r represents the number of items being chosen at a time.

Hence, in this case, n =  12, r = 5, which is = = 792.

Therefore, there are 792 ways to choose five books so that no two adjacent books are chosen.

10 cm

step-by-step explanation:

if the polygon is a rectangle, then the perimeter is x+x+y+y. using the values that you gave, the perimeter is 3+3+2+2=10cm.