Personalized Intelligent Triangle Light Youth 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. Let the good times roll in a durable T-Shirt that takes kids from school to play in an amazing array of colors. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar.