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Statistics

Question
CBSEENMA9003243

A traffic signal board, indicating ‘SCHOOL AHEAD’, is an equilateral triangle with side ‘a’. Find the area of the signal board, using Heron’s formula. If its perimeter is 180 cm, what will be the area of the signal board?

Solution

'a'   =  a
'b'   =  a
'c'   =  a
WiredFaculty
Area of the signal board
WiredFaculty
Perimeter = 180 cm
rightwards double arrow   'a' + 'b' + 'c' = 180
rightwards double arrow   a + a + a = 180
rightwards double arrow              3a = 180
WiredFaculty
rightwards double arrow space space space    a = 60  cm
therefore  Area of the signal board equals fraction numerator square root of 3 over denominator 4 end fraction straight a squared
           equals fraction numerator square root of 3 over denominator 4 end fraction left parenthesis 60 right parenthesis squared equals 900 square root of 3 space cm squared
Alternatively,
     space space space space space straight s space equals fraction numerator 3 straight a over denominator 2 end fraction equals 3 over 2 left parenthesis 60 right parenthesis equals 90 space cm
Area of the signal board
    WiredFaculty

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