Answer:
lengths of sides are 12 cm, 12 cm and 16 cm
Step-by-step explanation:
The perimeter of a triangle is the sum of the 3 sides.
let l be the length of the third side, then
l - 4 is the length of the two equal sides.
given the perimeter is 40 cm.
sum the 3 sides, equate to 40 and solve for l
l + l - 4 + l - 4 = 40 ( simplify left side )
3l - 8 = 40 ( add 8 to both sides )
3l = 48 ( divide both sides by 3 )
l = 16
and l - 4 = 16 - 4 = 12
the sides of the isosceles triangle are 12 cm , 12 cm and 16 cm
