Stack Exchange network consists of 178 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It only takes a minute to sign up.
Q&A for work
Connect and share knowledge within a single location that is structured and easy to search.
Can someone tell me why the answers highlighted in red ( 12 and pi/2 ) are wrong and how can I find the correct answers? The rest are correct
Required, but never shown