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In triangle ΔJKL, where k=87cm, l=76cm, and ∠J=82°, find the length of side j, rounded to the nearest centimeter.

A) 120 cm
B) 125 cm
C) 130 cm
D) 135 cm

User TccHtnn
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1 Answer

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Final answer:

To find the length of side j in triangle ΔJKL, we use the Law of Sines. By substituting the given values into the equation and calculating the values of sine, we find that side j is approximately 89.90 cm long.

Step-by-step explanation:

To find the length of side j in triangle ΔJKL, we can use the Law of Sines. The Law of Sines states that for any triangle, the ratio of the length of a side to the sine of its opposite angle is constant. In this case, we have the length of sides k and l, as well as the measure of angle J. So we can set up the following equation:

sin J / j = sin K / k

Now, we can substitute the given values into the equation:

sin 82° / j = sin K / 87

Since the sum of the angles in any triangle is 180°, we can find angle K by subtracting the measures of angles J and L from 180°:

K = 180° - J - L = 180° - 82° - (180° - J) = J - 98°

Now, substitute the value of K into the equation:

sin 82° / j = sin (82° - 98°) / 87

Now, solve for j:

j = (sin 82° × 87) / sin (82° - 98°)

Calculate the value of sin 82°, sin (82° - 98°), and substitute into the equation:

j ≈ (0.9917 × 87) / (0.9407) ≈ 89.90 cm

Therefore, the length of side j is approximately 89.90 cm.

User Reinhard Behrens
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