Question

If ∆ABC ≅ ∆DEF and ∠A = 40 degree

, ∠C = 60 dregree

, then find the measure of ∠E​

Answer 1

since ABC is congruent to DEF  

angle A = ang. D

ang. B = ang. E

ang C = ang. F..... (i)

by CPCT

also ang ( A + B + C) = 180

50 + B + C = 180  

from (i)

50 + B + 60 = 180

110 + B = 180  

B = 70