Find the perimeter and area of the hockey rink if it is 15 meters long and 90 decimetres wide.

First, you should translate the width of the hockey rink from decimetres to meters.
1 m = 10 dm.
We get:
90/10 = 9 meters.
In order to find the area of a hockey rink, you must multiply the value of its length and width.
15 * 9 = 135 m2
To determine its perimeter, the sum of the length and width of the hockey rink should be multiplied by 2 equal parts.
In this case, it will be:
2 * (15 + 9) = 2 * 24 = 48 meters.
Answer: The perimeter of the hockey rink is 48 meters, the area is 135 m2