How many sides does a circle have?

I am dry when I go inside, but wet when I am pulled outside.
The longer I am inside, the stronger I get
When I am completely out, I am wet and I literally sag
Who am I?

Before Mount Everest was discovered, what was the highest mountain in the world?

I have a clock(12-hour format) and both the needles of the clock overlap at 12:00.
After how much time, they will overlap again?

My thunder comes before the lightning; my lightning comes before clouds; my rain dries all the land it touches. What am I?

A person was found dead on a big green land with no trees or buildings around. When the police arrived, they found a piece of rock lying next to him and the man was wearing clothes comprising of red, blue and yellow colours.

Can you tell who the person is and what was the cause of death?

Give it food and it will live; give it water and it will die.

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

I am soft and cuddly that soothe your heart. But, If you pick my last name I am going to tear you all apart. Who am I?