STEP 1: find side $ a $
To find side $ a $ use formula:
$$ P = 4 \cdot a $$After substituting $P = 100\, \text{cm}$ we have:
$$ 100\, \text{cm} = 4 \cdot a $$ $$ a = \dfrac{ 100\, \text{cm} }{ 4 } $$ $$ a = 25\, \text{cm} $$STEP 2: find diagonal $ d1 $
To find diagonal $ d1 $ use formula:
$$ d_1^2 + d_2^2 = 4 \cdot a^2 $$After substituting $d_2 = 48\, \text{cm}$ and $a = 25\, \text{cm}$ we have:
$$ d_1 ^ {\,2} + \left( 48\, \text{cm} \right)^{2} = 4 \cdot \left( 25\, \text{cm} \right)^{2} $$ $$ d_1 ^ {\,2} + 2304\, \text{cm}^2 = = 2500\, \text{cm}^2 $$ $$ d_1 ^ {\,2} = = 2500\, \text{cm}^2 - 2304\, \text{cm}^2 $$ $$ d_1 ^ {\,2} = 196\, \text{cm}^2 $$ $$ d_1 = \sqrt{ 196\, \text{cm}^2 } $$$$ d_1 = 14\, \text{cm} $$STEP 3: find area $ A $
To find area $ A $ use formula:
$$ A = \dfrac{ d_1 \cdot d_2 }{ 2 } $$After substituting $d_1 = 14\, \text{cm}$ and $d_2 = 48\, \text{cm}$ we have:
$$ A = \dfrac{ 14\, \text{cm} \cdot 48\, \text{cm} }{ 2 }$$$$ A = \dfrac{ 672\, \text{cm}^2 }{ 2 } $$$$ A = 336\, \text{cm}^2 $$