Question

de is parallel to bc find angle A where bde is 105 degree and ceb is 80 degree and cbe is 30 degree

Answer 1

Answer:

Step-by-step explanation:

In triangle ABC, <A = 105, <B = 30 and AC = 8. How can i find the length of side AB?

<C = 180 - <A - <B = 180 - 105 - 30 = 45

By applying the sine rule sin A/BC = sin B/AC = sin C/AB, we have

sin 105/BC = sin 30/8 = sin 45/AB, or

BC = 8*sin 105/sin 30 = 15.45481332

AB = 8*sin 105/sin 45 = 10.92820323