This black t-shirt features a clever mathematical design perfect for a 13-year-old's birthday! The shirt proudly displays the square root of 169, alongside the text "YEARS OLD". Made from a comfortable material, this tee is ideal for everyday wear, birthday parties, or as a unique gift. Show off your love for math and celebrate turning 13 in style. A fun and unique statement piece that's sure to spark conversation. Get yours today and make a mathematical fashion statement!