Q. In △MNO,n=57 inches, m=69 inches and ∠M=58∘. Find all possible values of ∠N, to the nearest 10th of a degree.Answer:
Apply Law of Cosines: To find the angle ∠N, we can use the Law of Cosines, which relates the lengths of the sides of a triangle to the cosine of one of its angles. The Law of Cosines states that for any triangle ABC with sides a, b, and c opposite angles A, B, and C respectively, c2=a2+b2−2abcos(C). In our case, we can let side m be c, side ABC1 be b, and angle ABC3 be angle C.
Convert angle to radians: First, we need to convert angle ∠M from degrees to radians because the cosine function in most calculators requires the angle to be in radians. However, since we are looking for an angle and not calculating a cosine value directly, we can skip this step and use the degree measure directly in the Law of Cosines.
Use Law of Cosines to find cos(N): Now, we apply the Law of Cosines to solve for cos(∠N):n2=m2+o2−2⋅m⋅o⋅cos(∠N),where o is the length of the side opposite to angle ∠N, which we don't know yet, and n and m are the known sides. However, we realize that we cannot use the Law of Cosines directly to find angle ∠N because we do not have the length of side o.
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