Question

In triangle ABC and DEF A°=E°=40°,AB:ED=AC:EF and F°=65° ,then B°= ?

Answer 1

In triangle DEF,
E = 40
F = 65
D = 180-(40+65)(ASP of a triangle)
= 180-105
= 75
D = B(SAS congruency)
therefore,
B = 75

Answer 2

When you draw the figure , you'll get to know that both the triangles are similar by SAS similarity rule.
Therefore, E° = A°
F° = C°
D° = B°
Now the sum of three angles of triangle is 180 so......
A + B + C = 180°
40° + B + 65° = 180°
B = 180°- 105°
B = 75°
Thanks.
Hope this helps you.