The perimeter of a triangle is 584 cm. The interior angles measure 50°, 60° and 70°, respectively. What is the radius of the largest circle that can be cut from this triangle in centimeters?
Answers
Answer:
triangles with these angles are similar, and P is directly related to the picked side length.
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L = 10
Perimeter = 33.57197472
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Multiply L by 168/P
a 55.40335354
b 62.6343707
c 67.96227419
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Perimeter = 185.9999984
Area = 1630.43914
The radius of the largest circle that can be cut from the given triangle is 55 cm.
The perimeter of a triangle is 584 cm. The interior angles measure 50°, 60° and 70°, respectively.
We have to find the radius of the largest circle that can be cut from this triangle in centimetres.
Let a , b and c are sides of triangle.
now using Sine rule
here, A = 50° , B = 60° and C = 70°
∴ sin50°/a = sin60°/b = sin70°/c = k (let)
⇒a = sin50°/k , b = sin60°/k , c = sin70°/k
perimeter of triangle, a + b + c = 584
⇒sin50°/k + sin60°/k + sin70°/k = 584
⇒k = (sin50° + sin60° + sin70°)/584
Incircle is the largest circle that can be cut from this triangle. and it is found by the ratio of area of triangle to semiperimeter.
i.e., r = ∆/s
we know, area of triangle = 1/2 ab sinC = 1/2 bc sinA = 1/2 ca sinB
we can choose any of one
∴ ∆ = 1/2 ab sinC = 1/2 (sin50°/k)(sin60°/k) sin70°
= (sin50° sin60° sin70°)/2k²
= {584²(sin50° sin60° sin70°)}/{2(sin50° + sin60° + sin70°)²}
now Radius , r = {584²(sin50° sin60° sin70°)}/{2(sin50° + sin60° + sin70°)² × 584/2}
= {584(sin50° sin60° sin70°)}/(sin50° + sin60° + sin70°)²
= 55.04 cm ≈ 55 cm