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4 votes
In this triangle cos A/cos B

In this triangle cos A/cos B-example-1
User Rnoway
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2 Answers

5 votes
a/SinA = b/SinB = c/SinC (this is the Sin rule applicable for any triangle).
And here CosA/a = CosB/b = CosC/c
So CosA/SinA = CosB/SinB = CosC/SinC
or CotA = CotB = CotC
In a triangle this is possible only when A = B = C = 60 degrees.
So the trianle is equilateral.
And hence a = b = c = 2
Or area = [root(3)/4] * (2^2) = root(3). { Area of an equilateral triangle is [root(3)/4]*(a^2) }
User Searene
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8.3k points
2 votes

Answer:
(3)/(3) Or 1

Explanation:


\left[\begin{array}{ccc}Sine&(SinA)/(A)\\Rule&(SinB)/(B)\\&(SinC)/(C) \end{array}\right]


\left[\begin{array}{ccc}Cos&(CosA)/(A)\\Rule&(CosB)/(B)\\&(CosC)/(C) \end{array}\right]


\left[\begin{array}{ccc}(CosA)/(SinA)=(CosB)/(SinB)=(CosC)/(SinC) \end{array}\right]


\left[\begin{array}{ccc}CosA&=(3)/(4.24)\\CosB&=(3)/(4.24)\end{array}\right]

Additional Answers:

Area: T = 4.5

Perimeter: p = 10.24

Semiperimeter: s = 5.12

Angle ∠ A = α = 89.929° = 89°55'43″ = 1.57 rad

Angle ∠ B = β = 45.036° = 45°2'8″ = 0.786 rad

Angle ∠ C = γ = 45.036° = 45°2'8″ = 0.786 rad


Height: ha = 2.123

Height: hb = 3

Height: hc = 3


Median: ma = 2.123

Median: mb = 3.352

Median: mc = 3.352


Inradius: r = 0.879

Circumradius: R = 2.12


Vertex coordinates: A[3; 0] B[0; 0] C[2.996; 3]


Centroid: CG[1.999; 1]


Coordinates of the circumscribed circle: U[1.5; 1.498]

Coordinates of the inscribed circle: I[2.12; 0.879]


Exterior(or external, outer) angles of the triangle:

∠ A' = α' = 90.071° = 90°4'17″ = 1.57 rad


∠ B' = β' = 134.964° = 134°57'52″ = 0.786 rad


∠ C' = γ' = 134.964° = 134°57'52″ = 0.786 rad

User Kamal Paliwal
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8.4k points