The perimeter of the triangle is 13cm. its two sides are equal, and the third side is 3 cm.

| February 9, 2021 | education

The perimeter of the triangle is 13cm. its two sides are equal, and the third side is 3 cm. Find the length of two equal sides of the triangle.

We are given an isosceles triangle, since the sides of an isosceles triangle are equal to each other. It is necessary to find the length of the sides of the triangle.

The perimeter of any geometric figure is equal to the sum of the lengths of its sides.

Let’s write down the formula for the perimeter of an isosceles triangle:

P = a + a + b = 2a + b,

where P is the perimeter, a is the lateral side, b is the base of the isosceles triangle.

Let us find from the formula the side side a:

2a + b = P;

2a = P – b;

a = (P – b) ÷ 2;

Let’s calculate the length of the side:

a = (13 – 3) ÷ 2 = 10 ÷ 2 = 5 cm.

Answer: the other two sides of the triangle are 5 cm.



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