What is the next number in this matchsticks series riddle?

Let's play a word game. Following are some meaningless words that can be completed by adding random letters on either side of the word.

For example, the word "rdo" can be formed into "pardon".

Using the same technique, can you complete the given words?
ecalc
airb
rinci
tibac
uidel
gorit
igna
eyho

Count the number of triangles in the picture below:

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

John was working on a Chemical Mixture whose weight comprise 90% liquid and 10% solid. The total weight of the mixture is 20 pounds. After a while, John noticed that some of the liquid evaporated and now the liquid comprises just 50% of the weight.

What is the weight of the chemical mixture now?

Count The number of F's in the paragraph below:

"FINISHED FILES ARE THE RESULT OF YEARS OF SCIENTIFIC STUDY COMBINED WITH THE EXPERIENCE OF YEARS"

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

Can you find the dog hidden in a group of pandas?

How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

I hide my treasure in the ground, my tail is big and fluffy. If you spot me in a tree, please don’t call me scruffy. What am I?