Use the relationship between supplementary angles ∠a

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

59°
59 degrees

301°
301 degrees

121°
121 degrees

31°

1 answer

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

\[ m∠a + m∠b = 180° \]

Substituting the value of \( m∠b \):

\[ m∠a + 121° = 180° \]

Now, subtract 121° from both sides:

\[ m∠a = 180° - 121° = 59° \]

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

The correct response is 59°.