Dyma faint o arian wariodd Siwan mewn wythnos:
Llun \(\pounds{3}\); Mawrth \(\pounds{10}\); Mercher \(\pounds{7}\); Iau \(\pounds{18}\); Gwener \(\pounds{8}\); Sadwrn \(\pounds{21}\); Sul \(\pounds{5}\).
O osod y data hwn ar siart cylch, pa ongl fyddai'n cynrychioli dydd Sadwrn?