Answer:
Explanation:
The first step here is to find the 3rd angle inside the triangle.
SInce measure of all angles in a triangle is 180 degree,
mABC+mBCA+mCAB= 180
85+mBCA+56=180
mBCA=180-85-56=39 degree
Now, angles BCA, BCE and DCE are supplementary angles, their sum is equal to 180. So,
mBCA+mBCE+mDCE=180
39+mBCE+90=180
mBCE=180-90-39=51 degrees