Question

In ∆ABC, BC is produced to D. If ∠A:∠B:∠C::2:3:4 and AC ⊥ CE, find ∠ECD. *

Answer 1

Answer:

10 degree

Step-by-step explanation:

∠A:∠B:∠C::2:3:4

TRIANGLE ABC

A+B+C = 180

2x + 3x + 4x = 180

x = 20

then C = 4x = 4*20 = 80

We can write it as

ACB = 80

now

Since BCD is a straight line

then,

ACE + ECD + ACB = 180

90 + ECD + 80 = 180

ECD + 170 = 180

ECD = 10