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Given triangle KLM, KM=24
m

Given triangle KLM, KM=24 m-example-1
User Corrina
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2 Answers

2 votes

Consider the attached diagram. Segment KO is an altitude of the triangle, so KO ⊥ LM. ∠L has measure 180° -105° -30° = 45°, so ΔKOL is an isosceles right triangle.

If we let segment LO have measure 1, then KO also has measure 1 and KL has measure √(1²+1²) = √2 by the Pythagorean theorem.

ΔKMO is half of an equilateral triangle, so KM has measure 2, and MO has measure √(2²-1²) = √3 by the Pythagorean theorem.

Then the ratio of KM to LM is 2:(1+√3) and the ratio of KL to LM is √2:(1+√3). That is, ...

... KL = LM×(√2)/(1+√3) = (20√3)(√2)/(1 +√3)

... KL = (20√6)/(√3 +1) = (20√6)(√3 -1)/(3 -1) . . . . . with denominator rationalized

... KL = 30√2 -10√6 ≈ 17.9315

and

... KM = LM×2/(1+√3) = KL×√2

... KM = (30√2 -10√6)√2

... KM = 60 -20√3 ≈ 25.3590

== == == == == ==

The Law of Sines tells you ...

... KL/sin(M) = KM/sin(L) = LM/sin(K)

Then ...

... KL = sin(M)·LM/sin(K) = sin(30°)·20√3/sin(105°) ≈ 17.9315

... KM = sin(L)·LM/sin(K) = sin(45°)·20√3/sin(105°) ≈ 25.3590

User AlexGH
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4.5k points
4 votes

Answer:

  • ≈ 12 units

Explanation:

Since m∠1 = m∠2, KF is angle bisector of ∠K

In the ΔKFM we have:

  • ∠K = 34°/2 = 17°
  • ∠M = 15°
  • ∠F = 180° - (17° + 15°) = 148°
  • KM = 24 units

Using low of sines:

  • sin F / KM = sin M / KF
  • sin 148° / 24 = sin 15° / KF
  • KF = 24*sin 15°/ sin 148°
  • KF = 11.72 ≈ 12 units
User Scorpion King
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4.3k points