Final answer:
The value of sin 54° is √7/4.
Step-by-step explanation:
To find the value of sin 54°, we can use the fact that the angles 36° and 54° are complementary.
Since cos 36° is known to be three fourths, we can use the Pythagorean identity cos²θ + sin²θ = 1 to find sin 54°.
Solving for sin 54°, we have sin 54° = √(1 - cos² 54°).
Substituting cos² 54° = (3/4)², we get sin
54° = √(1 - (3/4)²)
= √(1 - 9/16)
= √(7/16)
= √7/4.
Therefore, the value of sin 54° is √7/4.