Answer:
a) 5.83 cm
b) 34.45°
Step-by-step explanation:
a) From Pythagoras theorem of right triangles, given right triangle ABC:
AB² + BC² = AC²
Therefore:
AC² = 5² + 3²
AC² = 25 + 9 = 34
AC = √34
AC = 5.83 cm
b) From triangle ACD, AC = 5.83 cm, AD = 4 cm and ∠A = 90°.
From Pythagoras theorem of right triangles, given right triangle ACD:
AD² + AC² = DC²
Therefore:
DC² = 5.83² + 4²
DC² = 34 + 16 = 50
DC = √50
DC = 7.07 cm
Let ∠ACD be x. Therefore using sine rule:

Answer:
yes and no,depends.
parrallel cant make any angles exept 180-straight line angle.



When is cos (x) = 0? <em>at 90° (aka π/2)</em>
Answer: 
Answer:
Yes a 1:3 ratio
Step-by-step explanation:
Yes triangle A is 3 times bigger than triangle B. So it takes 3 B triangles to make one A triangle.