Trigonometry

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Across
  1. 2. Chart-topping number
  2. 3. just hold tan upside down
  3. 6. measurement of triangles
  4. 7. additional secant
  5. 9. This t-ratio is given by the sun
Down
  1. 1. frequently used short form for 'second'
  2. 4. pokes through 2 points.
  3. 5. alpha beta and charlie form a figure
  4. 7. Bunkhouse Feature
  5. 8. Literal pronunciation of 'sign'