Question

Ppplllzzz hhhheeelllllllpppppp ​

Answer 1

Answer: CD = 12.7

Explanation:

Use Pythagorean Theorem or 30-60-90 rules to find that BC = 6√3

We know that ∠D = 55°, the opposite side (BC) = 6√3, and we are looking for the hypotenuse (CD).

`sin\ \theta=(opposite)/(hypotenuse)\\\\\\sin\ 55^o=(6\sqrt3)/(CD)\\\\\\\text{cross multiply to get:}\\\overline{CD}\cdot sin\ 55^o=6\sqrt3 \\\\\\\text{divide sin 55 from both sides to get:}\\\overline{CD}=(6\sqrt3)/(sin\ 55^o)\\\\.\qquad=12.68\\\\\\\text{rounded to 3 significant digits we get:}\\\overline{CD}=12.7`