To find height $ h $ use formula:
$$ V = \dfrac{ r ^{ 2 } \cdot h \cdot \pi}{ 3 } $$After substituting $ V = 23 $ and $ r = 1.75 $ we have:
$$ 23 = \dfrac{ 1.75 ^{ 2 } \cdot h \cdot \pi}{ 3 } $$$$ 23 \cdot 3 = 1.75 ^{ 2 } \cdot h \cdot \pi $$$$ 69 = 3.0625 \cdot h \cdot \pi $$$$ h = \dfrac{ 69 }{ 3.0625 \, \pi} $$$$ h = 7.1717 $$