#title: exercicios com $\pi$
#author: 
#let:

f a=[%pi, %pi/2 ,%pi/4  , 2 * %pi];

##f a=[6.2831853, 0.7853981625, 3.14159265, 1.570796325, ];

f b= #a*2 ;

n c=#b;

#question:

Quanto é $#a \times 2$?

#sugestion:
#resolution:
 $ #b $

 ou seja #c
#result:
 $ #b $
#Verify: