Answer:
x = 25.6
Step-by-step explanation:
As we can see, this is a right triangle, so there are known relationships
well to start we have to know the relationship between angles, legs and the hypotenuse
α = 43
a: adjacent = x
o: opposite
h: hypotenuse = 35
sin α = o/h
cos α = a/h
tan α = o/a
we see that it has (angle, adjacent, hypotenuse)
cos α = a/h
cos 43° = x / 35
cos 43° * 35 = x
25.59 = x
if we want to round to the nearest tenth
x = 25.59 = 25.6
Well you could factor it by dividing the entire equation by two...
x^2+8x-5=0
Answer:
19.1
Step-by-step explanation:
Let's assign some variables to this triangle.
angle A = 63°
angle B = unknown
angle C = 71°
side a = 18
side b = y
side c = x
By the law of sins, applicable to ALL triangles, we have:

Let's then take the equation for angles A and C, in order to isolate the c (which is our x to find).
we then have

So, the answer is the second one.