Avocado, Tomato and Cucumber Arugula Salad

Ingredients

 2 avocados,diced 

1 english cucumber, 

sliced 3 roma tomatoes,

 diced ¼ cup red onion, 

sliced 1 cup arugula 

2 Tablespoons olive oil 

2 Tablespoons lemon juice 

salt and pepper ¼ cup feta cheese