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Would you use the sine or cosine rule when only having two sides of the triangle?
Wiki User
∙ 12y ago
It depends upon what you already know.
If you know only two side lengths, neither rule is useful - you need to know at least one angle.
If you are trying to discover the length of the third side, use the cosine rule.
If you are trying to discover the other two angles, then use the sine rule. However, if the known angle is between the two known sides, the cosine rule will have to be used first to find the third side; then the sine rule can be used.
If you know two of the angles, you can calculate the third (if necessary) and use either rule to calculate the third side.
It depends on which two sides you are working with.
You use sine when working with the opposite and the adjacent sides.
You use cosine when working with the adjacent and the hypotenuse sides.
(You can remember this by the very silly little rhyme: Silly old Hitler caught awful headaches throughout our air-raids! The first letter of each word is: SOHCAHTOA which helps you remember. For example, the SOH means Sine = Opposite & Adjacent etc..)
Wiki User
∙ 12y ago
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What is the area of a triangle having sides of 22 cm by 62 cm by 48 cm?
Using the cosine and sine rules the area of the triangle works out as 457 square cm rounded.
What is given two sides and the included angle?
The cosine rule which is: a2 = b2+c2-2*b*c*cosine A This is used to find the third side of a triangle when the two other sides are known along with the angle between them. Used when the triangle is not a right angle.
How do you work out the angles in a triangle with only 3 sides and no angles?
use the inverse sine or cosine or tangent
What is the ratio of the adjacent and hypotenuse sides of a right triangle?
That's the cosine of the angle to which the 'adjacent' side is adjacent.
How do you calculate angles in a scalene triangle?
If you know the lengths of the sides, you can use the cosine rule. If you have information about other aspects of the triangle, then other formulae will apply.
The ratio of the adjacent and hypotenuse sides of a right triangle?
cosine
What is the area of a triangle having sides of 22 cm by 62 cm by 48 cm?
Using the cosine and sine rules the area of the triangle works out as 457 square cm rounded.
How do you find the interior angle in a triangle?
It depends on what information you have. If you have only the lengths of the three sides, you would need to use the cosine rule.
How do you find the cosine of a triangle?
For the length you apply this formula, after numbering the sides a²=b²+c²-2bcCosA
What is given two sides and the included angle?
The cosine rule which is: a2 = b2+c2-2*b*c*cosine A This is used to find the third side of a triangle when the two other sides are known along with the angle between them. Used when the triangle is not a right angle.
A ratio of the lengths of two sides of a right triangle?
Sine Cosine Tangent Cotangent Secant Cosecant
What is the ratio of the adjacent and hypotenuse sides of a right triangle?
That's the cosine of the angle to which the 'adjacent' side is adjacent.
How do you work out the angles in a triangle with only 3 sides and no angles?
use the inverse sine or cosine or tangent
How do you calculate angles in a scalene triangle?
If you know the lengths of the sides, you can use the cosine rule. If you have information about other aspects of the triangle, then other formulae will apply.
What is a triangle that has 2 sides?
A triangle having two sides does not exist. All triangles have three sides.
What is a triangle is a triangle having three congruent sides?
equilateral triangle
How do you work out the hypoteneuse side of an isosceles triangle if the triangle is not right-angled and two of the sides and the angle between them are known?
Use the cosine rule: a2 = b2+c2 - 2bc*cos A An isosceles triangle has two equal sides.
