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In ΔDEF, f = 33 inches, m∠F=140° and m∠D=5°. Find the length of e, to the nearest 10th of an inch.

User Hamani
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Final answer:

To find the length of side e in ΔDEF with given dimensions, we use the Law of Sines and find that e is approximately 19.8 inches to the nearest tenth.

Step-by-step explanation:

To solve for the length of side e in triangle ΔDEF, where we have the length of side f equals 33 inches, the measure of angle m∠F equals 140° and the measure of angle m∠D equals 5°, we can use the Law of Sines. The Law of Sines states that in any triangle, the ratio of the length of a side to the sine of its corresponding angle is constant. That is:

sin(D) / d = sin(E) / e = sin(F) / f

First, we calculate the measure of angle E using the fact that the sum of the angles in any triangle equals 180 degrees:

m∠E = 180° - m∠D - m∠F = 180° - 5° - 140° = 35°

Then we set up the ratio using the Law of Sines:

sin(D) / d = sin(E) / e

As we don't have the length of side d, we use side f and angle F:

sin(F) / f = sin(E) / e

sin(140°) / 33 = sin(35°) / e

Multiplying both sides by e and then by sin(35°) gives us:

e = f * sin(35°) / sin(140°)

After calculating with a calculator:

e = 33 * sin(35°) / sin(140°) ≈ 19.8 inches

So, the length of side e to the nearest tenth of an inch is approximately 19.8 inches.

User Dan McCallum
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