Question

please help me to solve the problems​

Answer 1

Answer:

60°

Explanation..

Given angle (A:B:C)= 3:2:1

Let angle( A: B : C )= 3x:2x:1x

therefore

angle A + angle B + angle C=180°

3x+2x+1x = 180°

6x=180

therefore,

x= 30°

Now,

substitute x = 30° in A:B:C

therefore, angle

A= 3*30°= 60°

B=2*30°=60°

C=1*30°=30°

since , angle ACE = 90° and angle ACB =30

we get , angle (ACB + ACE + ECD ) =180°

=30°+90°+ angle ECD=180°

therefore,angle ECD=180-120°

angle ECD=60°