Answer:
a = 22
Step-by-step explanation:
[tex]cot \: 4a = tan \: (a - 20)....(given) \\ \\ \implies \: tan(90 - 4a) = tan \: (a - 20) \\ [\because \: cot \theta = tan(90 \degree - \theta) ]\\ \\ \implies (90 - 4a) = tan(a - 20) \\ \\ \implies \: 90 + 20 = 4a + a \\ \\\implies \: 110 = 5a \\ \\ \implies \: a = \frac{110}{5} \\ \\ \huge \red{ \boxed{\implies \: a = 22}}[/tex]
