Answer:
126°
Step-by-step explanation:
m<D +m<E +m<F = 180°(sum of the interior angles of the triangle)
3x+18x+ 5x-2= 180°
26x= 180+2
26x= 182
x=182/26
x=7
So, m<E = 18x= 18(7) = 126°
