$($c$)$ A UU test was carried out on a saturated clay sample. The sample was originally

$75mm$ in diameter and $150mm$ high. A cell pressure of $100$kPa was used.

During shearing a peak load of $500N$ was recorded at a strain of $10\%.$

Determine the magnitude of the undrained shear strength $(c{u}_u)$ and the orientation

of the failure plane.