Hi Bre,
Since lines a and b are parallel, we know that in the image:
- ∡1 ⇔ ∡5
- ∡2 ⇔ ∡6
- ...
- ∡4 ⇔ ∡8
We're given the angle of ∡7, which is 114°. We can see that ∡7 + ∡8 will equal to 180° (since line b is a straight line) and since ∡8 ⇔ ∡4, we can deduct that ∡7 + ∡4 = 180°.
From here, it's just imputing the information and solving.
⇒ 114° + ∡4 = 180°
⇒ ∡4 = 180° - 114°
⇒ ∡4 = 66°
-Hope this helps!
Answer:
the cyclists rode at 35 mph
Step-by-step explanation:
Assuming that the cyclists stopped, and accelerated instantaneously at the same speed than before but in opposite direction , then
distance= speed*time
since the cyclists and the train reaches the end of the tunnel at the same time and denoting L as the length of the tunnel :
time = distance covered by cyclists / speed of cyclists = distance covered by train / speed of the train
thus denoting v as the speed of the cyclists :
7/8*L / v = L / 40 mph
v = 7/8 * 40 mph = 35 mph
v= 35 mph
thus the cyclists rode at 35 mph
You could do this in two ways, you could either subtract immediately or convert the time given in hours into minutes
STEP 1:
8:10
- 7:40
which will give 0:30
STEP 2:
8 hours 10 minutes into minutes is
(8 * 60) +10 = 490 minutes
7 hours 40 minutes into minutes is
(7*40) + 40 = 460 minutes
490 - 460
= 30minutes
