Can you count the number of triangles in the given figure?

Be active and find the killer in the picture Riddle below.

You have a three-gallon and a five-gallon measuring device. You wish to measure out four gallons.

Three doctors said that Bill was their brother. Bill says he has no brothers. How many brothers does Bill actually have?

A man has a barrel filled with oil that weighs 100 pounds, and then he puts something into it. Now the barrel weighs less than 100 pounds. What did he put in the barrel?

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

How many sides does a circle have?

If,
29 - 1 = 30
9 - 1 = 10
14 - 1 = 15

Based on similar logic, Can you prove that the below algebraic equation is true?
11 - 1 = 10 ?

What is always in front of you but can’t be seen?

What is the longest word in the dictionary?