Question

Use the relationship between supplementary angles ∠a
and ∠b
. What is m∠a
if m∠b=121°
?(1 point)
Responses

121°
121 degrees

301°
301 degrees

59°
59 degrees

31°

Answer 1

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

\[
m∠a + m∠b = 180°
\]

Substituting the value of \( m∠b \):

\[
m∠a + 121° = 180°
\]

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

\[
m∠a = 180° - 121°
\]
\[
m∠a = 59°
\]

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

The correct response is:

**59°**