Find the perimeter of an isosceles triangle with base AB if AB = 7m, BC = 8m.

To find the perimeter of a triangle, you first need to understand what the perimeter is. The perimeter is the sum of all the sides of a shape, in this case an isosceles triangle.
The length of AB (base) is 7 meters. Since the triangle is isosceles, its sides are equal to each other. This means that if the side of the triangle BC is 8 meters, then its other side AC is also 8 meters.
Perimeter formula: P = AB + BC + AC.
We get: P = 7 + 8 + 8 = 23 meters.
Answer: 23 meters is the perimeter of an isosceles triangle ABC.