3 coins touching each other, can you fit another one in the middle?

Math tutorial on solving a geometry puzzle. We have 3 circles, all with radius 1 and all tangent to each other. We would like to know the biggest possible circle that can fit in the gap. ----- Download 10 Precalculus Practice Tests with 200 fully solved problems:   / 1722797   ----- This channel is dedicated to creating helpful precalculus tutorials for high school and college students around the world. Thanks to these Patreon members for building this with me! 3Blue1Brown • Allison Lamery • Anthony Hunting • Anyway • Ben Delo • Caoimhe Seymour • charlie lewinski • Corey Rufener • CTAR • David I Miller • Doc Ockey • exchsac • Gramps • Hayden S • huguens nevelus • jappiesaus • Jessica • Johan Renko • Karl Tang-Wang • Manil Trivedi • Mark Pagura • MarkM • Mas • Michael ZHOU • Michelle Liang • Mister Hardware • Mizel Cluett • Nerd • Nicolai Lilly • Ricardo Murillo • Rohan • SaltyFishbutwithDream • Sebastian Correa • Sharnay Ampos • Steven McEwan • Subotai Baghatur • Terry Chang • Tomaz Mevlja • Torbjörn Karlsson • Whoever • Zero • Zhansu • Matthias Beeler • bontle sjm • 博鈞 林 (Updated: October 2026   / blackpenredpen  ) ----- #bprpmathbasics #math #algebra #precalculus