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Fig. 29
Bazele : AB, DC
<A=<D=90°
<B=360°-2×90°-60°=120°
Fig. 30
Bazele : EF, GH
<G=180°-102°=78°
<E=180°-45°=135°
Fig. 31
Bazele : KL, IJ
< I = < J (trapez isoscel) = 76°
<K=<L=(360°-2×76°)/2=104°
Fig. 32
Bazele : MN, OP
<M=180°-75°=105°
<O=180°-135°=45°