Wetting the cloth cover of your canteen on a hot day is a good or bad idea

bad due to the cloth getting hot and containing all heat captured inside of said canteen, making it hot and not very drinkable unless you like hot water

the sum of all the angles in a triangle are equal to 180

so you can add   the 3 given angles together to equal 180:

5y + 2y + 2y = 180

or since all three angles have the same letter, combine the 3 angles to equal 180:

9y = 180