Use the relationship between supplementary angles ∠a

Question

and ∠b
. What is m∠a
if m∠b=121°
?(1 point)
Responses

59°
59 degrees

301°
301 degrees

121°
121 degrees

31°
31 degrees

Answer 1

Supplementary angles are two angles that add up to 180 degrees. Given that \( m∠b = 121° \), you can find \( m∠a \) using the formula:

\[ m∠a + m∠b = 180° \]

Substituting the given value:

\[ m∠a + 121° = 180° \]

To find \( m∠a \), subtract 121° from both sides:

\[ m∠a = 180° - 121° \]

Calculating this gives:

\[ m∠a = 59° \]

So, the measure of angle \( a \) is \( 59° \).