The correct options are
A 8
B 6
Given that the perimeter of the right-triangle is 24 cm.
If x an y are the longer and shorter arms of the triangle respectively, then
x+y+10=24.
⟹y=14−x
Using Pythagoras' theorem, we have
x2+y2=102.
i.e., x2+(14−x)2=100
⟹x2+x2+196−28x=100
⟹2x2−28x+96=0
⟹x2−14x+48=0
⟹x2−8x−6x+48=0
⟹x(x−8)−6(x−8)=0
⟹(x−8)(x−6)=0
⟹x=8 and 6
If x=8, then y=14−x=14−8=6.
If x=6, then y=14−x=14−6=8.
Since x>y, we must have x=8 andy=6.
∴The longer and shorter sides of the triangle are 8 cm and 6 cm respectively.