Questions: Solve each triangle using the labels as shown in Illustration 1 sides to three significant digits and angles to the nearest tent
Illustration 1
12. B=17.5°, a=345 m, c=405 m
Transcript text: Solve each triangle using the labels as shown in Illustration 1 sides to three significant digits and angles to the nearest tent
Illustration 1
12. $B=17.5^{\circ}, a=345 \mathrm{~m}, c=405 \mathrm{~m}$
Solution
Solution Steps
Step 1: Find angle A using the Law of Sines
We are given B = 17.5°, a = 345 m, and c = 405 m. We can use the Law of Sines to find angle A:
sin(A) / a = sin(B) / b = sin(C) / c
sin(A) / 345 = sin(17.5°) / b = sin(C) / 405
sin(A) = (345 * sin(17.5°)) / 405
sin(A) ≈ 0.2550
A ≈ arcsin(0.2550)
A ≈ 14.8° or A ≈ 180° - 14.8° = 165.2°
Since the sum of angles in a triangle must be 180°, and B = 17.5°, if A = 165.2°, then A + B = 182.7° > 180°, which is impossible. Therefore, A ≈ 14.8°.
Step 2: Find angle C
The sum of angles in a triangle is 180°. We know A ≈ 14.8° and B = 17.5°, so: