For 1b), the other equal angle would be 70; the remaining angle would be 180-(70+70) = 180-140 = 40. For 1c), the other equal angle would be 45; the remaining angle would be 180-(45+45) = 180-90 = 90. For 1d), he saved 50/200; dividing this, we get 0.25; 0.25*100 = 25%. For 1e), he saved 28/560; dividing this, we get 0.05; 0.05*100 = 5%.