Personalized Intelligent Triangle Light Toddler Long Sleeve T-Shirt. Triangle with the letter A in the word triangle replaced with a percussion triangle with text, the instrument for intelligent people, is a funny gift design with attitude for percussionists, music teachers and students in orchestra and concert band. A classic for Fall, Winter and Spring, these long sleeve toddler t-shirts are sure to be a staple in your child's wardrobe. Whether layered or alone, this t-shirt is soft yet durable enough to stand up to your toddler's playtime demands.