Question

The perimeter of a triangle is 36cm and its side are in the ratio a:b:c=3:4:5, find the sides a,band c

Answer 1

3x + 4x + 5x = 36

12x = 36

x = 3
The sides are 9 cm , 12cm, 15cm

Answer 2

Answer:—

$\fbox\pink{a \:=\: 9\: cm , \:b \:=\: 12\: cm\: and \:c\: = \:15 cm }$

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Given:—

Perimeter of triangle is 36 cm

And it's sides are in ratio a:b:c = 3:4:5

Find the sides a, b and c

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Solution:—

$\fbox\pink{Perimeter\: of \: triangle\:=\: side\:×\:side\:×\:side }$

.

Now,

Let the sides be x

So, it will be 3x , 4x and 5x

.

• Perimeter given is 36 .

Perimeter = 3x + 4x + 5x

36 = 12x

$\dfrac{36}{12}$ = x

x = 3

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Now let's find the sides a, b and c !

Side A :

a = 3x

a = 3(3)

a = 9 cm

.

Side B :

b = 4x

b = 4(3)

b = 12 cm

.

Side C :

c = 5x

c = 5(3)

c = 15 cm

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Let's check !

LHS :

a + b + c

= 3x + 4x + 5x

= 3(3) + 4(3) + 5(3)

= 9 + 12 + 15

= 36 cm

.

LHS = RHS = 36 cm

Hence , checked !

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Therefore, a = 9 cm , b = 12 cm and c = 15 cm