Will someone plz help me

Is the figure congruent? yes or no?

The product of 3 and a number increased by 8 is 31

Megan and desmond each add the same amount of water to their aquarium megan makes 5 ml of chemical solution with every gallon of water for her aquarium desmond mixed 8 ml of chemical solution for every 2 gallon of the water for his aquarium.