? (2) Answer: 0.505438+02

? (3) Answer: 0.9999

? (4) Answer: 3.438+0

I forgot how to do it ... sorry.

Three. Tan 55 = B/24 B ≈ 34.2756

? sin 35 = 24/°c？ c≈4 1.8427

Four. AD=3，∠ b = 60？ According to trigonometric function BD=√3? AB=2√3

The triangle BDA∽BAC is BD/AB = AB/BC.

√3/2√3=2√3/BC？ Get BC=4√3.

There is something wrong with this question. The waist of an isosceles triangle is larger than the bottom, and your 5∶8 is not in accordance with the law.

Intransitive verb 20 nautical miles

7. I don't understand

I hope my answer is helpful to you!

Typing is very hard, hope to adopt! ! ! ! !