Question

3. If the sides of a friangle one produced in order, then
the sum of the three exteroir angles formed is​

Answer 1

In the figure, by exterior angle property, you have
ACD = A+ B
CBF = A+ C
BAE = B+ C
Adding the above equations, you get
ACD +CBF +BAE = A+ B +A+ C + B+ C
= 2 (A+ B +C)
= 2 180॰ (angle sum of a )
ACD +CBF +BAE =360o
That is the sum of the exterior angles = four right angles. (360॰ = 490॰)
HOPE IT HELPS