Question

triangle has a perimeter of 60 CM if two sides are of length 18 centimetre and 22cm find the length of the third side​

Answer 1

Given:

• Perimeter of a triangle = 60cm
• Length of side a = 18cm
• Length of side b = 22cm

To find:

• Length of side c?

Solution:

• Let's consider ABC is a triangle.

Where,

Length of side a = 18cm

Length of side b = 22cm

Length of side c = x

• Let length of side c be x.

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« Now, By using perimeter formula,

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$\dashrightarrow \textsf{ \textbf{Perimeter = a + b + c}}$

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$\dashrightarrow \quad\sf 18 + 22 + x = 60$

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$\dashrightarrow \quad\sf 40 + x = 60$

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$\dashrightarrow \quad\sf x = 60 - 40$

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$\dashrightarrow \quad\sf x = 20$

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« Now, Let's verify it,

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$\dashrightarrow \quad\sf18 + 22 + x = 60$

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Putting the value of x,

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$\dashrightarrow \quad\sf 18 + 22 + 20 = 60$

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$\dashrightarrow \quad\sf 60 = 60$

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LHS = RHS

Hence, Verified!

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$\underline{ \textsf{ \textbf{Additional \: knowledge...}}}$

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$\; \; \; \; \; \; \;{\sf{\bold{\leadsto Area \: of \: rectangle \: = \: Length \times Breadth}}}$

$\; \; \; \; \; \; \;{\sf{\bold{\leadsto Perimeter \: of \: rectangle \: = \:2(length+breadth)}}}$

$\; \; \; \; \; \; \;{\sf{\bold{\leadsto Perimeter \: of \: square \: = \: 4 \times sides}}}$

$\; \; \; \; \; \; \;{\sf{\bold{\leadsto Area \: of \: square \: = \: Side \times Side}}}$

$\; \; \; \; \; \; \;{\sf{\bold{\leadsto Area \: of \: triangle \: = \: \dfrac{1}{2} \times breadth \times height}}}$

$\; \; \; \; \; \; \;{\sf{\bold{\leadsto Area \: of \: paralloelogram \: = \: Breadth \times Height}}}$

$\; \; \; \; \; \; \;{\sf{\bold{\leadsto Area \: of \: circle \: = \: \pi b^{2}}}}$

$\; \; \; \; \; \; \;{\sf{\bold{\leadsto Perimeter \: of \: triangle \: = \: (1st \: + \: 2nd \: + 3rd) \: side}}}$

$\; \; \; \; \; \; \;{\sf{\bold{\leadsto Perimeter \: of \: paralloelogram \: = \: 2(a+b)}}}$

$\; \; \; \; \; \; \;{\sf{\bold{\leadsto CSA \: of \: sphere \: = \: 2 \pi r^{2}}}}$

$\; \; \; \; \; \; \;{\sf{\bold{\leadsto SA \: of \: sphere \: = \: 4 \pi r^{2}}}}$

$\; \; \; \; \; \; \;{\sf{\bold{\leadsto TSA \: of \: sphere \: = \: 3 \pi r^{2}}}}$

$\; \; \; \; \; \; \;{\sf{\bold{\leadsto Diameter \: of \: circle \: = \: 2r}}}$

$\; \; \; \; \; \; \;{\sf{\bold{\leadsto Radius \: of \: circle \: = \: \dfrac{d}{2}}}}$

$\; \; \; \; \; \; \;{\sf{\bold{\leadsto Volume \: of \: sphere \: = \: \dfrac{4}{3} \pi r^{3}}}}$

$\; \; \; \; \; \; \;{\sf{\bold{\leadsto Area \: of \: circle = \: \pi r^{2}}}}$

$\; \; \; \; \; \; \;{\sf{\bold{\leadsto Circumference \: of \: circle \: = \: 2 \pi r}}}$

$\; \; \; \; \; \; \;{\sf{\bold{\leadsto Diameter \: of \: circle \: = \: 2r}}}$

Answer 2

★ Given :

Triangle has a perimeter of 60 CM if two sides are of length 18 centimetre and 22 cm.

★ To Find :

The length of Third Side

★ Solution :

Let the third Side be x

Perimeter = a + b + c

➤ 18 + 22 + x = 60

➤ 40 + x = 60

➤ x = 60 - 40

➤ x = 20

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Now, putting the value of x

➥ 18 + 22 + 20 = 60

➥ 40 + 20 = 60

➥ 60 = 60

Hence Verified ✔

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The Third side is 20 cm.