Answer: 45°.
- A 30°
- B 45°
- C 60°
- D 90°
Correct answer: B. 45°
Explanation: sin 45° + cos 45° = 1/√2 + 1/√2 = 2/√2 = √2. So θ = 45°.
Unit circle with standard angles 0, 30, 45, 60, 90 degrees; at 45 degrees the point is (cos45, sin45) = (1/sqrt2, 1/sqrt2).
Concept context
Ratios, identities, and applications in triangles