If angle $b$ measures $60°$, what is the measure of the angle that is complementary to angle $b$?

• A. $120°$
• B. $90°$
• C. $60°$
• D. $30°$

Answer: (D)

Verified step by step guidance

1. Recall that complementary angles are two angles whose measures add up to 90 degrees.
2. Given that angle \( b \) measures \( 60^\circ \), set up the equation for the complementary angle \( x \) as \( b + x = 90^\circ \).
3. Substitute the known value of \( b \) into the equation: \( 60^\circ + x = 90^\circ \).
4. Solve for \( x \) by subtracting \( 60^\circ \) from both sides: \( x = 90^\circ - 60^\circ \).
5. Simplify the right side to find the measure of the complementary angle.