The length of the lateral side of an isosceles triangle is 18 cm, and its perimeter is more than 65 cm

The length of the lateral side of an isosceles triangle is 18 cm, and its perimeter is more than 65 cm. How long can the base of the triangle have?

To answer this question, let us first recall some of the properties of isosceles triangles. In particular, the fact that an isosceles triangle is called a triangle in which two sides are equal, as well as the fact that equal sides of an isosceles triangle are called lateral, and not an equal side – the base. Also, remember that the perimeter is the sum of the lengths of all the sides of the shape. That is, to find how long the base of a given triangle can have, it is necessary to multiply the length of the side by two and subtract the result from the given perimeter. Let’s calculate:

18 * 2 = 36

65 – 36 = 29

Answer: the length of the base of the given triangle must be more than 29 centimeters.



One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.