In , . If and , determine the value of…

MATHEMATICS · Single correct · GCSE · Mathematics · Geometry and Measures · Geometry and Measures

Problem

\triangle DEF

DE = DF

. If

\angle E = 3x + 5^{\circ}

and

\angle F = 2x + 25^{\circ}

, determine the value of

x

. (a) 25 (b) 20 (c) 30 (d) 12