One side of the triangle is 20 cm, the second side is 3 times longer than the third. Calculate the two unknown sides

| April 9, 2021 | education

One side of the triangle is 20 cm, the second side is 3 times longer than the third. Calculate the two unknown sides of a triangle if its perimeter is 52 cm. One of the adjacent angles is 5 times larger than the other. Find the degree measures of these angles.

We find two unknown sides of the triangle, if one side is known = 20 cm, the other is 3 times longer than the thirds and the perimeter is also known equal to 52 cm.

The perimeter of the triangle is P = a + b + c.

Let us denote the third side by x, and substitute the second 3 x into the formula, that is, make up the equation.

52 = 20 + 3 x + x. We solve the equation.

52 – 20 = 4 x.

4 x = 32.

x = 32/4.

x = 8 cm

third side = 8 cm.

second = 8 cm * 3 = 24.

Answer: sides of a triangle = 20 cm, 24 cm, 8 cm.

Let us find the degree measures of angles if one of them is 5 times larger than the other.

And so the sum of adjacent angles is 180 °.

Let’s make the equation 5 x + x = 180

6 x = 180.

x = 180/6.

x = 30.

30 ° one angle, and the second 180 – 30 = 150.

Answer: 30 ° and 150 °



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.