Question

answer this question with step by step explanation class 7 And who ever will give me the correct answer I will mark him or her as brainlist​

Answer 1

Answer:

∠ECD =  60°

Step-by-step explanation:

Let the ratios of the angles A, B, & C  be   $3x : 2x : 1x$

Then, we know that sum of all the angles of a triangle measures 180°

∴  $3x + 2x + 1x = 180$

⇒ $6x = 180$

⇒  $x = \frac{180}{6}$

⇒ $x$ = 30

Thus, now putting the value of 'x' we get the three angles

∠A ⇒ $3x$ =  3(30) = 90°

∠B ⇒ $2x$  =  2(30) = 60°

∠C ⇒ $x$    = 30°

Now, we also know that a straight line is of 180°

so,  ∠ACB + ∠ACE + ∠ECD =  ∠BCD

    ⇒  30°  +   90°   + ∠ECD = 180°

    ⇒   120° + ∠ECD = 180°

    ⇒  ∠ECD = 180° - 120°

                     =  60° (ans)

Hence,  ∠ECD =  60°

Hope this will help you !!!

Pls mark as brainliest !!!

Answer 2

Answer:

45°

Step-by-step explanation: