Draw some expanding arrows

Canvas, 10 bytes

⇵-×<ｎ¹［↔｝］

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R, 69 bytes

for(i in 1:scan()-1)cat('<'[i%%2],rep('-',i/2),'>'[!i%%2],'
',sep='')

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• -5 bytes thanks to @Giuseppe
• -3 bytes thanks to @Robert S.

Java (JDK), 81 bytes

n->{for(int i=0;i<n;)System.out.printf(i%2<1?"<%s%n":"%s>%n","-".repeat(i++/2));}

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Explanations

n->{                  // int-accepting consumer
 for(int i=0;i<n;)    //  for each i from 0 to n-1 included
  System.out.printf(  //   output on stdout with a pattern
   i%2<1              //    if i is even:
    ?"<%s%n"          //     use the left-arrow pattern
    :"%s>%n",         //    else: use the right-arrow pattern
   "-".repeat(i++/2)  //    fill the "%s" in the pattern with i/2 dashes, and increment i
  );                  // 
}                     //