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Draw triangle ABC with side BC as the base. The measure of angle A=60 degrees. If a perpendicualr is drawn from B to side AC, the height is 8. What is the length of side AB?

User JohannesNE
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1 Answer

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Final answer:

Side AB in triangle ABC with a 60-degree angle at A and a height of 8 from B to AC is found using the sine function, yielding AB ≈ 9.24 units.

Step-by-step explanation:

To find the length of side AB in triangle ABC with a 60-degree angle at A and a perpendicular height of 8 from B to AC, we can use trigonometry. Specifically, we will use the sine function, which relates the ratio of the opposite side to the hypotenuse in a right-angle triangle. In this case, since the height from B to AC is perpendicular, triangle ABC is divided into two right-angled triangles with angle A being 60 degrees in one of them.

The sine of angle A (60 degrees) is equal to the opposite side (height from B to AC, which is 8) divided by the hypotenuse (AB). Hence:

sin(60°) = Opposite / Hypotenuse

sin(60°) = 8 / AB

Since sin(60°) is √3/2, we have:

√3/2 = 8 / AB

Therefore, AB can be calculated as follows:

AB = 8 / (√3/2)

AB = 8 × 2 / √3

AB = 16 / √3

Finally, rationalizing the denominator, we get:

AB = 16√3 / 3

AB ≈ 9.24 (to two decimal places)

Thus, the length of side AB in triangle ABC is approximately 9.24 units.

User Gocht
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