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Ipotenusa $\overline{AC}= 52\,cm;$
cateto minore $\overline{BC}= \dfrac{1}{4}×\overline{AC}+7 = \dfrac{1}{4}×52+7 = 13+7 = 20\,cm;$
cateto maggiore $AB= \sqrt{(\overline{AC})^2-(\overline{BC})^2} = \sqrt{52^2-20^2} = 48\,cm$ $(teorema\,di\,Pitagora);$
perimetro $2p= \overline{AC}+\overline{BC}+\overline{AB} = 52+20+48 = 120\,cm;$
area $A= \dfrac{\overline{AB}×\overline{BC}}{2} = \dfrac{48×20}{2} = 480\,cm^2.$
BC= 1/4*52= 13 +7= 20 cm
AB ( con Pitagora) = radice quadrata 52^2 - 20^2= 2304= 48cm
Perimetro = 52+20+48= 120 cm
Area= 48*20/2= 480 cm quadrati