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Use trig to find the legs of ABC if the base is AC and the height is BC (round to nearest tenth)​

Use trig to find the legs of ABC if the base is AC and the height is BC (round to-example-1
User Deisy
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1 Answer

4 votes

Answer:

GIVEN :-

  • ∠A = 15°
  • Length of AB (hypotenuse) = 60 ft

TO FIND :-

  • Length of BC
  • Length of AC
  • Area of ΔABC

FACTS TO KNOW BEFORE SOLVING :-


  • \sin \theta = (Side \: opposite \: to \: \theta)/(Hypotenuse)

  • \cos \theta = (Side \: adjacent \: to \: \theta)/(Hypotenuse)

SOLUTION :-

In ΔABC ,


  • \sin 15 = (BC)/(60)


=> 0.2588... = (BC)/(60)


=> BC = (0.2588....) * 60 = 15.5291..... ≈ 15.5 ft


  • \cos 15 = (AC)/(60)


=> 0.9659..... = (AC)/(60)


=> AC = (0.9659.....) * 60 = 57.9555..... ≈ 58 ft

Area of ΔABC =
(1)/(2) * 58 * 15.5 = 449.5 \:ft^2

User Jason Antman
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