The perimeter of the CDE triangle is 19/20 m; CD = 2/5 m; CD is 1 / 10m larger than DE. Find CE.

In this task, we find the sides of the triangle;

In this triangle, we know its perimeter and one of the sides;

Let’s remember what a perimeter is;

The perimeter is the sum of the lengths of all sides;

Since we know that the side of the triangle CD = 2 / 5m, and the side DE is 1/10 m less than the side of CD, so we can write such an equation;

DE = CD – 1/10;

Let’s substitute the data;

DE = 2/5 – 1/10 = (4 – 1) / 10 = 3 / 10m;

Knowing the two sides and the perimeter, we find the third side;

CE = P – CD – DE;

Let’s substitute the data;

CE = 19/20 – 2/5 – 3/10 = (19 – 2 * 2 – 3 * 2) / 20 = (19 – 4 – 6) / 20 = 9 / 20m.