1. **State the problem:** We have a triangle ABC with angles A, B, and C. Angle A is 21 degrees more than angle B, and angle C is 36 degrees more than angle B. We need to find angle B. 2. **Recall the triangle angle sum rule:** The sum of the interior angles of a triangle is always 180 degrees. 3. **Set up variables and equations:** Let angle B be $x$ degrees. Then angle A = $x + 21$ degrees. Angle C = $x + 36$ degrees. 4. **Write the equation for the sum of angles:** $$x + (x + 21) + (x + 36) = 180$$ 5. **Simplify the equation:** $$3x + 57 = 180$$ 6. **Isolate $x$:** $$3x = 180 - 57$$ $$3x = 123$$ 7. **Divide both sides by 3:** $$\cancel{3}x = \cancel{3}41$$ $$x = 41$$ 8. **Conclusion:** Angle B is $41$ degrees.