The measure of ∠1 =

55
62.5
110

both lines are 5 so both outsides are 125 degrees each = 250 degrees

 a full circle = 360

 so 360-250 = 110 degrees between the 2 lines

angle 1 would be half that so 110/2 = 55

 angle 1 = 55 degrees

step-by-step explanation:

given that there are two triangles j'k'l' and jkl>

the former is got by dilating the second one.

when drawn on a grid, (graph paper) coordinates of vertices of first triangle is

(6,12)j, (9,6)k and (12,9)l

side jk has length = distance between j and k

=

side j'k'=distance between j' and k'

=

ie j'k'l' has sides 1/3 of that of corresponding sides of jkl.

hence scale factor of 1/3 is used to get j'k'l'from jkl