STEP 1: find side $ b $
To find side $ b $ use Pythagorean Theorem:
$$ a^2 + b^2 = d^2 $$After substituting $a = 6\, \text{cm}$ and $d = 10\, \text{cm}$ we have:
$$ \left( 6\, \text{cm} \right)^{2} + b^2 = \left( 10\, \text{cm} \right)^{2} $$ $$ b^2 = \left( 10\, \text{cm} \right)^{2} - \left( 6\, \text{cm} \right)^{2} $$ $$ b^2 = 100\, \text{cm}^2 - 36\, \text{cm}^2 $$ $$ b^2 = 64\, \text{cm}^2 $$ $$ b = \sqrt{ 64\, \text{cm}^2 } $$$$ b = 8\, \text{cm} $$STEP 2: find area $ A $
To find area $ A $ use formula:
$$ A = a \cdot b $$After substituting $a = 6\, \text{cm}$ and $b = 8\, \text{cm}$ we have:
$$ A = 6\, \text{cm} \cdot 8\, \text{cm} $$$$ A = 6\, \text{cm} \cdot 8\, \text{cm} $$$$ A = 48\, \text{cm}^2 $$