Question

17) Vertically opposite angle of an obtuse angle is always ______________.

18) For ∆ABC and ∆PQR, given that ∟B = ∟R, ∟C = ∟P and BC = RP, then _______________ is true

Answer 1

Answer:

17)Smaller than 180° and greater than 90°

18)ABC-RPQ

19)48°

20)greater than the third side