Trionglau hafalochrog ac isosgeles
Mae gan driongl hafalochrog \({3}\) ochr hafal a \({3}\) ongl hafal.
Mae gan driongl isosgeles \({2}\) ochr hafal a \({2}\) ongl hafal.
Question
Beth ydy maint ongl \({p}\)?
Triongl isosgeles ydy hwn, felly \({p}\) ydy’r ddwy ongl waelod.
Mae’r onglau mewn triongl yn adio i \({180}^\circ\), felly:
\({p} + {p} + {40} = {180}\)
\({2p} + {40} = {180}\)
\({2p} = {140}\)
\({p} = {70}^\circ\)