What is the Value of sin 40°?

sin(40°) ≈ 0.6428 (rounded to 4 decimal places), representing a moderate acute angle sine value.

The sine of 40 degrees is:

• Exact value: sin(40°) = 0.64278760...
• Rounded: ≈ 0.6428 or 0.643

Relationships:

• sin(40°) = cos(50°) (complementary angles)
• sin(40°) = sin(140°) (supplementary angles)

This is a commonly used value in trigonometry problems and engineering calculations.

Importants Points:

• Value: sin(40°) ≈ 0.6428
• Complementary: cos(50°) = sin(40°)
• Type: Acute angle sine value