The perimeter of any triangle is the sum of its 3 sides.
If the base of an isosceles triangle is 11 and its perimeter is 39, then it has a height of 12.87.
The answer depends on what information you have but, basically, you need to add together the lengths of the three sides of the triangle.
Assuming that neither of the sides of equal length is the base, Perimeter = Base + 2*Slanted sides.
It is the sum of the lengths of its sides.
If you mean "isosceles" triangle, the perimeter is the sum of twice the known side plus the base.
The perimeter of any triangle is the sum of its 3 sides.
If the base of an isosceles triangle is 11 and its perimeter is 39, then it has a height of 12.87.
You cannot since there is insufficient information.
The answer depends on what information you have but, basically, you need to add together the lengths of the three sides of the triangle.
Assuming that neither of the sides of equal length is the base, Perimeter = Base + 2*Slanted sides.
It is the sum of the lengths of its sides.
That's not enough information to solve the problem.
I don't see any isosceles triangle below.In general, the perimeter is the sum of the lengths of all sides. Note that in an isosceles triangle, two of the three sides have the same length.
Perimeter of the isosceles triangle: 16.2+16.2+8.1 = 40.5 cm
Lengths of: equal side+equal side+base = perimeter
Add the lengths of the three individual sides.