If in oblique ΔABC side a=13 m, side b=6 m, and side c=9 m, then use the Law of Cosines to find the measure of ∠A .(1 point)

Question

Responses

15 degrees
15 degrees

119 degrees
119 degrees

50 degrees
50 degrees

63 degrees
63 degrees
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Answer 1

To find the measure of angle A, we can use the Law of Cosines, which states:
c^2 = a^2 + b^2 - 2ab * cosC

Plugging in the values we have:
9^2 = 13^2 + 6^2 - 2*13*6*cosA
81 = 169 + 36 - 156cosA
81 = 205 - 156cosA
-124 = -156cosA
cosA = -124 / -156
cosA = 0.79487179487
A = cos^(-1)(0.79487179487)
A ≈ 37 degrees

So, the measure of angle A is approximately 37 degrees.