##### Across

**5.**A ____ strip is a one sided surface you get by gluing together two sides of a tape**8.**repeated exponentiation**9.**Statement assumed to be true**10.**The plus sign (+) originally stood for this Latin word**11.**Less than zero**12.**Ten to the power of hundred**13.**Simplest platonic solid, triangular pyramid**16.**The most beautiful equation in mathematics is named after whom?**17.**Symbol used for the roots of numbers**18.**Earliest known mathematician**19.**A field of mathematics in which a donut and a cup are considered equal

##### Down

**1.**square root of minus one**2.**Six-sided polygon**3.**2π**4.**A statement thought to be true but which proof is not yet known**6.**Platonic solid with the most sides**7.**Numbers 2,13,57 are ____**14.**Written at the end of a proof**15.**Self-contradictory statement