Angles a and b are supplementary angles. What is the value of m∠a if m∠b=43°?(1 point)

If two angles are supplementary, their sum is 180 degrees.

So, if m∠b = 43°, then:

m∠a + m∠b = 180°
m∠a + 43° = 180°

Subtracting 43° from both sides, we have:

m∠a = 180° - 43° = 137°

Therefore, the value of m∠a is 137°.