Understand and use the trigonometric ratios to find the size of an unknown angle,, or the length of an unknown side in a right-angled triangle.

gm-u2-t2-s1-d1

Interactive

Sine, cosine, tangent as ratios of sides

manipulative

Drag the top vertex of a right triangle and pick the reference angle; opposite, adjacent and hypotenuse re-label themselves and the three ratios update live.

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