Is π11 a real number?​

Pyramid shown has a square base that is 18 inches on each side has a surface area of 164 square inches what is the slant height

If tan2a=cot(a+60), find the value of a, where 2a is an acute angle

Me answer this question: -2/3p + 1/5 - 1 + 5/6p i think the simplified expression is 1/6p - 4/5 correct me if i'm wrong, and explain it! if i have it right, just tell me. you so