Trionglau hafalochrog ac isosgeles

Mae gan driongl hafalochrog \({3}\) ochr hafal a \({3}\) ongl hafal.

Diagram triongl hafalochrog

Mae gan driongl isosgeles \({2}\) ochr hafal a \({2}\) ongl hafal.

Diagram triongl isosgeles
Question

Beth ydy maint ongl \({p}\)?

Diagram swm triongl isosgeles

Triongl isosgeles ydy hwn, felly \({p}\) ydy’r ddwy ongl waelod.

Mae’r onglau mewn triongl yn adio i \({180}^\circ\), felly:

\[{p} + {p} + {40} = {180}\]

\[{2p} + {40} = {180}\]

\[{2p} = {140}\]

\[{p} = {70}^\circ\]

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