Functions (MCR3U) · Trigonometric Functions

Exact trigonometric ratios from special triangles

Find the exact value of a trig ratio at a special angle (0, 30, 45, 60, 90 degrees) using reference triangles. Unlimited questions, five difficulty levels, and a full worked solution every time — free.

Practice this skill Curriculum: MCR3U-TF1.1

Try one

Find the exact value of sin(45deg).

  • √(2)/2
  • √(3)
  • 1
  • 12

Answer: sqrt(2)/2

See one solved, step by step

Find the exact value of cos(45deg).

  • 12
  • 0
  • √(2)/2
  • √(3)
📘 Worked solution
1In a 45-45-90 triangle, the sides are in the ratio 1 : 1 : √(2).Every special angle comes from one of these reference triangles, or straight from the axes.
2cos(45deg) = √(2)/2cos = adjacent/hypotenuse.

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