The lenghts of two in an isosceles triangle are 8 cm and 4 cm then the perimeter of the triangle is cm 1. 16
2. 8
3. 20
4. 12

Step-by-step explanation:

sides are 4cm, 8cm, 8cm ( because isosceles triangle have 2 sides equal )

so, perimeter = sum of all sides

= 4 + 8 + 8

step-by-step explanation:

points a and b are equidistant from the desired line, so the line you find by using them will go through point r.

using points other than a and b will give the desired line only if they are equidistant from r. if they are randomly located, the perpendicular line you create will not necessarily go through point r, hence will not be a solution to the problem.