Question on: JAMB Mathematics - 2005

< OUT = < OTU

< OUT = (\frac{180^o - 70^o}{2} = \frac{110^o}{2} = 55^o)

< RUT = 180^o - 100^o = 80^o

< RUO = < RUT - < OUT

= 80^o - 55^o

= 25^o