c=15 cm
a=3x
b=4x - katety
c^2=a^2+b^2
15^2= (3x)^2+(4x)^2
225= 9x^2+16x^2
25x^2=225
x^2=225:25
x^2=9
x=3
a=3*3= 9
b=4*3=12
p=a+b+c= 9+12+15=36
c=15 cm
a=3x
b=4x - katety
c^2=a^2+b^2
15^2= (3x)^2+(4x)^2
225= 9x^2+16x^2
25x^2=225
x^2=225:25
x^2=9
x=3
a=3*3= 9
b=4*3=12
p=a+b+c= 9+12+15=36