Use trigonometry
sin 42 = a / 21
a = 21 sin 42 = 14.05
Remark
You are dealing with a right angle triangle. You can use one of Sin(x) Cos(x) or Tan(x). Since the Hypotenuse is involved and since you are given the adjacent side, Cos(71) is what you will need.
Solution
H = BC
Cos(x) = adjactent / hypotenuse
Cos(71) = 6.3 / H Multiply both sides by H
H * Cos(71) = 6.3 Divide by Cos(71)
H = 6.3 / cos(71) Cos(71) = 0.32557
H = 6.3 / 0.32557 Divide
H = BC = 19.351 Answer
If the machine makes 5 buttons at a time,and each doll gets 5 buttons then one doll is the answer
we don't have solutions !!
The gcf of 15 and 70 is 5
