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Flashcards · Maths · Geometry and Measures

Trigonometry in Right-Angled Triangles

16 cards

  1. What is the hypotenuse?

    The longest side of a right-angled triangle, opposite the right angle.

  2. What is the opposite side?

    The side across from the angle you are using.

  3. What is the adjacent side?

    The side next to the angle you are using, apart from the hypotenuse.

  4. What is the formula for sine?

    \(\sin\theta = \dfrac{O}{H}\).

  5. What is the formula for cosine?

    \(\cos\theta = \dfrac{A}{H}\).

  6. What is the formula for tangent?

    \(\tan\theta = \dfrac{O}{A}\).

  7. What does SOH CAH TOA stand for?

    Sine is Opposite over Hypotenuse, Cosine is Adjacent over Hypotenuse, Tangent is Opposite over Adjacent.

  8. What is \(\sin 30^\circ\)?

    \(\dfrac{1}{2}\).

  9. What is \(\cos 60^\circ\)?

    \(\dfrac{1}{2}\).

  10. What is \(\tan 45^\circ\)?

    1.

  11. What is \(\sin 45^\circ\) and \(\cos 45^\circ\)?

    Both \(\dfrac{\sqrt{2}}{2}\).

  12. What are \(\sin 60^\circ\) and \(\cos 30^\circ\)?

    Both \(\dfrac{\sqrt{3}}{2}\).

  13. What is \(\tan 60^\circ\)?

    \(\sqrt{3}\).

  14. What is \(\sin 0^\circ\), \(\sin 90^\circ\) and \(\cos 90^\circ\)?

    0, 1 and 0.

  15. How do you find an angle when you know two sides?

    Use the inverse function, such as \(\tan^{-1}\left(\dfrac{O}{A}\right)\).

  16. What is the side opposite a \(30^\circ\) angle in terms of the hypotenuse?

    Half of the hypotenuse.