• Equal sides of an isosceles triangle = 2cm shorter than the length of the third side.
• Length of the third side.
Let the third side be c.
Also, two equal sides be a and b.
According to the question,
[tex] \longmapsto [/tex] a = ( Third side - 2 ) cm
[tex] \longmapsto [/tex] a = ( c - 2 ) cm
Similarly, length of b(second side) will also be same as a and b are two equal sides of an isosceles triangle.
[tex] \longmapsto [/tex] b = ( c - 2 ) cm
Now, we know that :
★ Perimeter of ∆ = Sum of all sides
[tex] \longmapsto [/tex] 35 = a + b + c
[tex] \longmapsto [/tex] 35 = (c - 2) + (c - 2) + c
[tex] \longmapsto [/tex] 35 = c - 2 + c - 2 + c
[tex] \longmapsto [/tex] 35 = c + c + c - 2 - 2
[tex] \longmapsto [/tex] 35 = 3c - 4
[tex] \longmapsto [/tex] 35 + 4 = 3c
[tex] \longmapsto [/tex] 39 = 3c
[tex] \longmapsto [/tex] [tex] \sf \dfrac{39}{3} [/tex] = c
[tex] \longmapsto [/tex] 13 = c
So, third side of the triangle is 13 cm.