Question

Practice set 3.1
In figure 3.8. ACD is an exterior angle of ABC
B-40°, ZA= 70°. Find the measure of ZACD​

Answer 1

Answer:

In figure 3.8, ∠ACD is an exterior angle of ΔABC. ∠B =40°,∠A=70°.

the measure of ∠ACD = 110°

Step-by-step explanation:

in a triangle sum of all angles = 180°

∠ABC  + ∠BAC +  ∠ACB = 180°

=> ∠B + ∠A +  ∠ACB = 180°

=> 40° + 70° + ∠ACB = 180°

=> ∠ACB = 70°

∠ACB + ∠ ACD = 180°  ( straight line)

=> 70° + ∠ ACD = 180°

=> ∠ ACD = 110°