Can you count the number of lines in the below picture?

I get hot but I never sweat,
I cook food but I am not a chef,
I have a door but you can't enter me,
I have a light but I am not a lamp.
Who am I?

What has a ring but no finger?

Can you make four (4) nines (9) equal 100?

By using all numbers, i.e. 123456789 and subtraction/addition, operators number 100 can be formed in many ways.
Example: 98 + 7 + 6 - 5 - 4 - 3 + 2 - 1 = 100

But if we add a condition use of the number 32 is a must. Then there are limited solutions.
One of such solution is: 9 - 8 + 76 + 54 - 32 + 1 = 100

Can you tell me any other solution?

Can you find the key in the picture below?

How many triangles can you count in the figure given?

I have a head like a cat and feet like a cat, but I am not a cat. What am I?

I have lakes with no water, mountains with no stone and cities with no buildings. What am I?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?