Respuesta :

Answer:

50 degrees

Step-by-step explanation:

If angle A and angle B are complementary, that would mean that their sum is 90 degrees. A + B = 90 . We know that angle A is 40, so 40 + B = 90. It becomes a one step equation. Subtract both sides by 40. 90 - 40 = 50. Angle B is equal to 50 degrees.

Answer:

50 degrees

Step-by-step explanation:

we know that

If two angles are complementary, then their sum is equal to 90 degrees

so

A+B=90°

we have

A=40°

substitute and solve for B

40°+B=90°

B=90°-40°=50°