The base of the isosceles triangle is 10 cm larger than the lateral one. Find the perimeter

The base of the isosceles triangle is 10 cm larger than the lateral one. Find the perimeter of the triangle. If its side is 4 dm.

Given:

Isosceles triangle;

Base -? 10 cm more lateral;

Lateral side – 4 dm.

Find: Perimeter.

Decision:

To calculate the perimeter of a given isosceles triangle, you need to know its sides, so we will find the base. But first, let’s bring the units of measurement in line with each other:

1) 4 dm = 4 * 10 cm = 40 cm.

10 cm more than the side means that to calculate the base, you need to add 10 cm to the side:

2) 40 + 10 = 50 (cm) – base.

Find the perimeter (base + two sides):

3) 50 + 2 * 40 = 50 + 80 = 130 (cm).

Answer: 130 cm (or 13 inches).