Question

4. An isosceles triangle has equal sides of 18 cm each. Find the third side if the perimeter of
triangle is 50 cm​

Answer 1

Answer:

From the question it is given that, one of the two equal sides is 18cm. Let us assume the third side be x. Therefore, length of third side of isosceles triangle is 14 cm.

Answer 2

$\huge{\underline{\underline{\sf{\bold{\pink{Given\::}}}}}}$

• $\sf{One \:of \:the\: two\: equal\: sides\: is\: 18\:cm.}$
• $\sf{Perimeter\: of \:an\: isosceles \:triangle \:is\: 50\:cm}$

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$\huge{\underline{\underline{\sf{\bold{\pink{Find\::}}}}}}$

• $\sf{Third\:side\:of\:isosceles\:triangle}$

${ }$

$\huge{\underline{\underline{\sf{\bold{\pink{Solution\::}}}}}}$

• $\small\sf{We\: know \:the, \:isosceles \:triangle \:contains\: two \:equal \:sides.}$

• $\small\sf{We\: know\: that, \:perimeter \:of \:isosceles \:triangle\: =\: sum \:of \:all\: sides}$

$\bf{Let \:us \:assume\: the\: third\: side\: be\: x.}$

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$\bf{Then,}$

$\:\:\:\:\:\::\:\Longrightarrow\sf\:{50\: =\: 18 \:+ \:18 \:+ \:x}$

$\:\:\:\:\:\::\:\Longrightarrow\sf\:{50 \:= \:36 \:+ \:x}$

$\:\:\:\:\:\::\:\Longrightarrow\sf\:{x\: =\: 50\: -\: 36}$

$\:\:\:\:\:\::\:\Longrightarrow\sf\:{x\: =\: 14\: cm}$

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$\purple{\bold{\dag}}\:{\underline{\small{\sf{Therefore, \:length \:of\: third \:side\: of\: isosceles\: triangle \:is\:{\bold{ 14\: cm}}}}}}.$