Respuesta :

Answer:

20 cm is the length of third side of triangle

Step-by-step explanation:

Length of 1st side = a

Length of 2nd side = 10cm = b

Length of 3rd side = 15cm = c

So,

Perimeter of triangle = 45 cm

a+b+c = 45cm

a + 10 + 15 = 45 cm

.'. a = 45-25 cm

= 20 cm

The midline or midsegment has a length equal to half of the third side.

Therefore, the length of the third side is 45 cm × 2 = 90 cm.

Response:

  • The length of the third side is 90 cm

Which theorem can be used to find the length of the third side?

Given:

The length of the midline = 45 cm

Required:

The length of the third side

Solution:

The midline is the line joining the midpoint of two sides of a triangle.

According to the midsegment theorem, the midline of a triangle is

parallel to the third side and has a length equal to half the length of the

third side.

Which gives;

The length of the mid line = [tex]\mathbf{\frac{1}{2}}[/tex] × The length of the third side

Let x represent the length of third side, we have;

45 = [tex]\frac{1}{2}[/tex] × x

Which gives;

The length of the third side, x = 2 × 45 cm = 90 cm

Learn more about the midsegment theorem here:

https://brainly.com/question/24600215