Question

nks:
a) Perimeter of a triangle is 57 cm. if its two sides are 18 cm and 13 cm, then third side will
be​

Answer 1

Given

• Perimeter of Triangle and it's two sides.

To find

• The third side of the Triangle.

Solution

$\sf{Perimeter = 57cm }$

$\sf\blue{First \ side = 18cm}$

$\sf\red{Second \ side = 13cm}$

$\sf{Third \ side = x}$

For now, let the third side be $x$

• To find the first side we have to add both first and second sides.
• Then, subtract the addition of both sides to the Perimeter.

$\sf\blue{18cm + 13cm + x = 31cm \ x}\\\\Perimeter - Addition \ of \ two \ numbers.$

$\sf\purple{57cm - 31cm = 26cm}$

•°• Hence, verified that the third side of Triangle is 26cm

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Diagram

$\setlength{\unitlength}{1 cm}\begin{picture}(0,0)\thicklines\qbezier(1, 0)(1,0)(3,3)\qbezier(5,0)(5,0)(3,3)\qbezier(5,0)(1,0)(1,0)\put(2.85,3.2){ \bf A }\put(0.5,-0.3){ \bf C }\put(5.2,-0.3){ \bf B }\end{picture}$

• AB = 18cm
• BC = 13cm
• CA = 26cm

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Answer 2

Step-by-step explanation:

Perimeter = 57 cm

First Side = 18 cm

Second Side = 13 cm

Third side = x

Let's find the third one x

$18cm + 13cm + x = 31cm \: x$

Perimeter - Addition of two no.

57 - 31 = 26 cm

•°• Hence, verified that the third side of Triangle is 26cm

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