CLASS 9 · LEARNING KNOWLEDGE
Sine, cosine and tangent
How it works
Sine and cosine relate a leg to the hypotenuse; tangent relates both legs. Opposite and adjacent legs are always named relative to the considered angle. Calculate in degrees.
Note
sin α=G/H; cos α=A/H; tan α=G/A.
sin α=G/H; cos α=A/H; tan α=G/A.
An example
A right-angled triangle has a hypotenuse of 6 cm and angle α=65°. Calculate the opposite side to α. Round to two decimal places. Give the result in cm.
sin α=G/H ⇒ G=6·sin(65°). Calculator in degree mode. Result: 5.44 cm.
Try it yourself now
50 Exercises · three difficulty levels · selection and number input
To the learning unit →Own explanation and own practice exercises by AmyMath. Subject reference framework: KMK Educational Standards Mathematics ESA/MSA. The topic assignment may vary by federal state.