I hope i not fail this test someone help

the answer to your question is pie

A: is irrational number

B: is rational number

C: is irrational number

D: as a natural or whole number, including 9, can also be written as a fraction p1 they are all rational number. hence 9 is a rational number

so D is the the answer

Given that sin A=0.725 is an acute angle in a right angled triangle we are required to find cos A
sin A=opposite/hypotenuse
sin A=0.725=29/40
this implies that
opposite=29
hypotenuse=40
using the Pythagorean theorem we can calculate the adjacent hence the cosine function
c^2=a^2+b^2
thus
40^2=29^2+b^2
b^2=40^2-29^2
b^2=759
b=sqrt759
b=27.54995436~27.55
hence 
cos A=27.55/40=0.68875