\VDDdef P(0,0)Q(5,0)R(2,3.5)
\VDDdef A(6,0)B(11,0)C(8,3.5)
\VDDdcanvas1.2:1
  \VDDdlpolygon ABC
  \VDDcinscribedcircle\length:N:ABC
  \VDDlcirclepointletter N:B:1
  \VDDdpoint N
  \VDDdcircle N:\length{}
  \VDDdlpolygon PQR
  \VDDcdeellijn l:PQR
  \VDDdhalfline l
  \VDDcdeellijn l:RPQ
  \VDDdhalfline l
  \VDDcdeellijn m:QRP
  \VDDdhalfline m
  \VDDcintersect M:lm
  \VDDllinelinepointletter ml:MP:-1:1
  \VDDdeflinepoint l:PQ
  \VDDcleadline m:l:M
  \VDDcintersect S:lm
  \VDDcplength\length:MS
  \VDDdcircle M:\length{}
  \VDDlangleequal PQMMQR
  \VDDlangleequal QRMMRP
  \VDDlangleequal RPMMPQ
\VDDdcanvasend

