ABCE is a cyclic quadrilateral. AED and BCD are straight lines. AC= CD, angle ABC= 45 degrees and angle ACE = 20 degrees. Work out angle ECD

∠ECD  is 110°

Step-by-step explanation:

For a cyclic quadrilateral,

∠ABC + ∠AEC = 180°

Therefore ∠AEC = 180° - 45° = 135°

∠CAE + ∠ACE + ∠AEC = 180° (Angles in a triangle)

Therefore ∠CAE =  180 - 20 - 135 = 25°

∠CAE = ∠CDA = 25° (Base angles of isosceles triangle ΔCAD)

∠CED + ∠AEC = 180°(Sum of angles on a straight line)

Therefore ∠CED + 135° = 180°

∠CED = 180° - 135° = 45°

∠ECD + ∠CED + ∠CDA = 180°

Therefore ∠ECD  = 180° - (∠CED + ∠CDA)

∠ECD  = 180° - (45° + 25°) = 110°

Therefore, ∠ECD  = 110°.

6. 104

7. 52/37

8. 2704

9. 140608

10. -52

11. |52|=52

12. 1/52

13. 156

14. 26

15. 40

16. 37

17. -364

18. 53 1/3

19. 50.96

20. 43 2/3

21. 78

22. 50.75

23. 47.63

24. 163.28

25. 10400

26. 338

27. 208

28. 2704 square inches

29. 312 square meters

30. don't know what its asking, tell me so i can tell you

31. 8490.56

32. 52 degrees would be an acute angle

33. 128 degrees

34. 20.8

35. 39

36. 208