1Bring a pot of lightly salted water to a boil; cook beans in boiling water until bright green and slightly tender, 3 to 5 minutes. Drain green beans and plunge into ice water until cold; drain.
2Toss green beans, radishes, and cucumbers together in a large bowl.
3Whisk olive oil and vinegar together in a small bowl until the oil emulsifies into the vinegar; season with salt and pepper. Drizzle dressing over salad and toss to coat.