Question

solve it out.... ??!!​

Answer 1

$\sf{\bold{\purple{\star{\underline{\underline{Given}}}}}}$

Perimeter = 30cm

equal sides = 12cm

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$\sf{\bold{\purple{\star{\underline{\underline{To\: Find }}}}}}$

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Area = ??

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$\sf{\bold{\purple{\star{\underline{\underline{Solution}}}}}}$

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let the unknown side be x

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$\sf{\star{\boxed{\orange{\frak{ Perimeter = sum \: of \: all \: sides }}}}}$

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$\sf : \implies\:{\frak{ 30 = 12 + 12 + x }}$

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$\sf : \implies\:{\frak{ 30 = 24 + x }}$

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$\sf : \implies\:{\frak{ x = 30 - 24}}$

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$\sf : \implies\:{\frak{ x = 6 }}$

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All the sides of the triangle are 6cm , 12cm and 12cm

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$\sf{\star{\boxed{\orange{\frak{ Semi\: perimeter = \dfrac{perimeter}{2} }}}}}$

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$\sf : \implies\:{\frak{ Semi perimeter = \dfrac{30}{2}}}$

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$\sf : \implies\:{\frak{ Semi\: perimeter = 15cm }}$

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$\sf{\star{\boxed{\orange{\frak{ Area = \sqrt{s(s-a)(s-b)(s-c)} }}}}}$

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$\sf : \implies\:{\frak{ Area = \sqrt{ 15 ( 15 - 12 ) ( 15 - 12 )( 15 - 6) }}}$

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$\sf : \implies\:{\frak{ Area = \sqrt{15\times 3\times 3 \times 9}}}$

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$\sf : \implies\:{\frak{ Area = \sqrt{15\times 3\times 3 \times 3\times 3 }}}$

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$\sf : \implies\:{\frak{ Area = 9 \sqrt{15}}}$

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$\sf : \implies\:{\frak{ Area = 9\times 3.88}}$

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$\sf : \implies\:{\frak{ Area = 34.92cm^2}}$

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$\sf{\star{\boxed{\green{\frak{ Area = 34.92cm^2 }}}}}$

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Answer 2

Answer:

area=69.84cm²

Step-by-step explanation:

perimeter = side + side + side

30=12+12+base

base= 6cm

by Pythagoras theorem,

height = root144-9

height = root135

height = 3root15= 11.64cm

area = 11.64×6

area=69.84cm²