Answer:
89 meters
Step-by-step explanation:
We know it's 9 + "the height of the triangle".
Fortunately, the height of the triangle (let's call it y) can be computed from:
y^2 + 18^2 = 82^2 (Pythagoras theorem).
y^2 = 82^2 - 18^2 = 6724 - 324 = 6400
y = 80 (or y = -80 but it doesn't make sense in geometry).
so x = y + 9 = 89;
Answer:
Step-by-step explanation:
B
2
3
Let the distance of two consecutive stones are x, x+1.
In ΔBCD, we have
tan60
o
=
x
h
⇒x=
3
h
.....(i)
In ΔABC, we have
tan30
o
=
x+1
h
⇒
3
1
=
x+1
h
⇒
3
h
+1=
3
h ......[from equation (i)]
⇒
3
2h
=1
⇒h=
2
3
km
solution
Cross multiply.
5.4x=9*25.8
5.4x=232.2 Divide both sides by 5.4
x=43
See attachment for math work and answer.
The key is Esther travelled the same distance - x - in both her morning and evening commute.
45(time she took in the morning, or p) = x
30(time she took in the evening, or q) = x
Therefore 45(p) = 30(q), or divide both sides by 5 and get 9(p) = 6(q). I know you can divide it further, but these numbers are small enough and it's not worth the time.
Since the whole trip took an hour, (p + q) = 60min, and so, p = 60-q.
Therefore 9(60-q) = 6q or 540-9q = 6q. So 540 = 15q, which makes q = 36. If q = 36, then by (p+q)=60, p (the time she took in the morning) must equal 24.
45 miles per hour, her speed in the morning, times (24/60) hours, her time, makes 18 miles travelled in the morning. If you check, 30 miles per hour times (36/60) hours also makes 18 miles in the evening.
<span>Hope that makes a little sense. And I also hope it's right</span>
