Answer:
30°
Explanation:
because the sum of all interior angles in a triangle is 180 degrees
180°= ∡ADE+∡DAE+∡AED
∡ADE = 180°-∡DAE -∡AED
because the diagonals are perpendicular so they form 90° angles, and ∡BRC≅∡AED(vertical angles)
∡AED =90
To find ∡DAE we need to find the value of y
11y+2 =90
11y =90-2
y=88/11
y=8
∡DAE=7y+4=7 ·8 +4= 56+4 =60°
now we know what we need to find ∡ADE
∡ADE = 180°-∡DAE -∡AED
∡ADE = 180°-60° -90°
∡ADE = 30°