Explanation : Let 2x, 3x, 5x and 8x be the angles of the quadrilateral.
Sum of angles of a quadrilateral = 360 °
⇒ 2x+3x+5x+8x=360o
⇒ 18x=360° ⇒ x=20°
Now, smallest angle = 2x = 2 x 20° = 40o
Complement of the smallest angle = 90o- 40° = 50°...(i)
Largest angle=8x =8 x20o =160°
Supplement of the largest angle= 180° -160° = 20° ... (ii)
Now, sum of the supplement of largest
angle and complement of smallest angle= 20o +50°= 70o