# प्लैनम बोरेयम

1. [1] and [2] give Vastitas Borealis starting at 54.7°N and Planum Boreum at 78.5°N. The radius of Mars is approximately 3400 km, so ${\displaystyle d={\frac {78.5-54.7}{360}}\times 2\pi \ \times 3400{\mbox{ km}}=1412{\mbox{ km}}}$