Q. In △FGH,g=190cm,f=900cm and ∠F=27∘. Find all possible values of ∠G, to the nearest 10th of a degree.Answer:
Law of Sines Formula: To find the possible values of angle G, we can use the Law of Sines, which states that the ratio of the length of a side of a triangle to the sine of the opposite angle is constant for all sides and angles in the triangle. The formula is:sin(A)a=sin(B)b=sin(C)cwhere a,b,c are the lengths of the sides, and A,B,C are the opposite angles.
Calculate Sine of Angle F: First, we need to find the sine of angle F, which is given as 27 degrees. We can use a calculator to find this value.sin(27∘)≈0.4540
Set Up Ratio with Law of Sines: Now, we can set up the ratio using the Law of Sines with the given sides g and f, and the known angle F.sin(F)f=sin(G)gsin(27∘)900=sin(G)190
Solve for Sine of Angle G: Next, we solve for sin(G).sin(G)=900190⋅sin(27∘)sin(G)≈900190⋅0.4540sin(G)≈90086.26sin(G)≈0.09584
Find Angle G using Inverse Sine: To find angle G, we take the inverse sine (arcsin) of sin(G).G≈arcsin(0.09584)Using a calculator, we find that:G≈5.5∘
Check Second Possible Value for Angle G: However, since the sine function is positive in both the first and second quadrants, there could be another possible value for angle G in the second quadrant. To find this, we use the fact that sin(180∘−G)=sin(G).180∘−G≈180∘−5.5∘180∘−G≈174.5∘
Validate Valid Solution for Angle G: We must check if this second possible value for angle G is valid in the context of a triangle. The sum of angles in any triangle is 180 degrees. Since we already have angle F as 27 degrees, the sum of angles G and the third angle H must be 180∘−27∘=153∘. If angle G were 174.5 degrees, the sum of angles G and H would exceed 180 degrees, which is not possible in a triangle. Therefore, the only valid solution for angle G is the one in the first quadrant.
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