8. Triangular & Circular Functions
8.01 Trigonometric functions as right triangle ratios
Interactive practice questions
Evaluate $\sin\theta$sinθ within $\triangle ABC$△ABC.
The angle at vertex $B$B, $\angle ABC$∠ABC, is marked with a double blue arc, and is labeled as $\theta$θ. The vertical side $AC$AC is opposite $\angle ABC=\theta$∠ABC=θ, and measures $8$8 units, as labeled. The horizontal side $BC$BC is adjacent $\angle ABC=\theta$∠ABC=θ, and measures $6$6 units, as labeled. The angle at vertex $A$A, $\angle BAC$∠BAC, is marked with a single blue arc and is labeled as $\alpha$α.
Easy
< 1min
Evaluate $\cos\theta$cosθ within $\triangle ABC$△ABC. Express your answer as a simplified fraction.
Easy
< 1min
Evaluate $\sin\theta$sinθ within $\triangle ABC$△ABC. Express your answer as a simplified fraction.
Easy
< 1min
Consider the triangle in the figure. If $\sin\theta=\frac{4}{5}$sinθ=45:
Easy
3min
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