Question 982145


Let &nbsp;<B>x</B>&nbsp; be the measure of the angle &nbsp;<I>L</I><B>D</B>: &nbsp;&nbsp;x = m(<I>L</I><B>D</B>)&nbsp; (in degrees).


Then the measure of the angle &nbsp;<I>L</I><B>E</B>&nbsp; be &nbsp;3<B>x</B>, &nbsp;and the measure of the angle &nbsp;<I>L</I><B>F</B>&nbsp; be &nbsp;3<B>x</B> - 9° &nbsp;degrees.


Since the sum of interior angles of a triangle is equal to 180°, &nbsp;you have an equation


x + 3x + (3x - 9) = 180.


Simplify and solve it:


7x - 9 = 180,


7x = 180 + 9,


7x = 189,


x = {{{189/7}}} = 27°.


Hence, &nbsp;m(<I>L</I><B>D</B>) = 27°, &nbsp;m(<I>L</I><B>E</B>) = 3*27° = 81°, and &nbsp;m(<I>L</I><B>E</B>) = 81° - 9° = 72°.