Solution:

The boy on the right is the one. The piece of his shirt is with the deceased girl, as indicated.

Solution:

The thief turned out to be Anthony, who cunningly concealed the watch inside a bucket.

Solution:

Cup2

As you can see, the flow of coffee to all cups is blocked. However, Cup 2 can be filled when the coffee overflows from the pipe, as demonstrated in the picture below.

Solution:

The kids have 4 slices of pizza in their hands but only three pieces are missing from the pizza box.

Solution:

The Girl

Solution:

Line - C

Explanation:
A^2= 3^2 + 6^2 => 9+36 => 45
B^2= 5^2 + 5^2 => 25+25 => 50
C^2= 6^2 + 4^2 => 36+16 => 52
D^2= 7^2 + 1^2 => 49+ 1 => 50

Solution:

A

The ladder of B is about to break.

Solution:

The pregnant lady.

The detective Byomkesh Bakshi noticed that the pregnant women look 6-7 months pregnant in January, May, and even in July. So that pregnant lady is the thief we are looking for and must be faking her pregnancy.

Solution:

Chicken-8

Explanation:
Let's start with distinct features

Chicken-2 has an extra toe.
Chicken-3 has fewer tail feathers.
Chicken-5 has only one thigh crease.
Chicken-6 has an extra feather around the neck.
Chicken-7 is looking up.
Chicken-8 has a longer butt crease.

But this riddle is not about the features. The different chicken is 8 as cannot be seen by any chicken.

Solution:

19