Trigonometry
sine, cosine and tangent of acute and obtuse angles, values for 30°, 45° and 60°, the Pythagorean identity and tangent as sine over cosine, the law of cosines, area of a triangle from the sine of an angle, type of a triangle from its sides
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Compute
sin 45° · cos 30°
Compute the tangent of the acute angle α
In a right triangle the leg opposite the acute angle α is 72 cm, the adjacent leg is 30 cm, and the hypotenuse is 78 cm.
Compute the length of the third side
Two sides of a triangle are 15 cm and 24 cm, and the angle between them is 60 degrees.
The angle α is acute. Find the value of the expression
sin²α + 4cos²α, if sin α = 2/5
Compute the sine of the obtuse angle α
cos α = −5/9
Decide whether this triangle is acute, right or obtuse
A triangle has sides 25 cm, 24 cm and 7 cm.
Compute the tangent of the acute angle α
sin α = 45/53
Compute the area of the triangle
Two sides of a triangle are 42 cm and 29 cm, and the angle between them is 135 degrees.
Compute the length of the leg opposite the 30-degree angle
In a right triangle the hypotenuse is 16 cm and one of the acute angles is 30 degrees.
Is this number positive, negative or equal to zero?
cos 116° · cos 148°
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