The measure of \angle B∠B is 26 degrees.
Since complementary angles have measures that add up to 90 degrees, we can set up the equation:
(4x+24)° + (3x-4)° = 90°
Combining like terms, we get:
7x + 20 = 90
Subtracting 20 from both sides, we get:
7x = 70
Dividing both sides by 7, we find the value of x:
x = 10
Substituting the value of x back into the expression for m\angle B∠B, we get:
m\angle B=(3x-4)° = (3(10)-4)° = 26°
Therefore, the measure of \angle B∠B is 26 degrees.