Answer: Complain
Step-by-step explanation:
Gripe- express a complaint or grumble about something, especially something trivial.
The polar coordinate system.
Answer:

Step-by-step explanation:
If the population increases at a rate of 4% per annum, then:
In year 1:

Where
is the initial population and
is the population in year n
In year 2

It can also be written as:

Taking out common factor

Taking out common factor (1 + 0.04)

Taking out again common factor 
Simplifying

So

This is the equation that represents the population for year n
Then, in 4 years, the population will be:

24, 32 , 40. Divide through by 8
3, 4, 5,
The 3 , 4, 5 reminds of the Pythagorean triple, which is a right angled triangle.
So a triangle with sides 24, 32, 40 is a right angled triangle.
Option A.