Answer:
Step-by-step explanation: ???
Answer:
(a)
angle bisector
(b)
altitude
(c)
perpendicular bisector
Step-by-step explanation:
Answer:
62.8yd
Step-by-step explanation:
formula for circumference of a circle = 2 π r
The perimeter is 4 semi circles, so 2 full circles. The diameter is 10yd and the radius is half the diameter, so the radius is 5yd
working:
2 x π x 5 = 31.4yd
31.4 x 2 = 62.8yd
Pic 1
90 - 33 = 57
m<P = 180 - 57
m<P = 123
answer is <span>B. 123°
</span>
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pic2
m<P = 90 - 30
m<P = 60
answer is
<span>C. 60°</span>
Let the train's original speed be s. Recall that distance = (speed)(time). Here, 150 miles = s(time), or 150 = s*t. If its original speed is increased by 5 mph, then the time required tomake the trip is 1 hour less than before;
distance = speed times time, so
150 mi = (s+5)(t-1). Let's eliminate t and solve for s:
Since 150 = s*t, t = 150/s. Subbing 150/s for t in the 2nd equation, we get:
150 s
150 mi = (s+5)(150/s - 1), or 150 = (s+5)(------- - ---- )
s s
Mult. both sides by s to elim. the fraction(s):
150s = (s+5)(150 - s)
Then 150s = 150s - s^2 + 750 - 5s, or
0 = -s^2 - 5s + 750
or 0 = s^2 + 5s - 750
Thus, 0 = (s-25)(s+30), and the roots are s=25 and-30. Only a positive original speed makes sense, so the answer is s = 25 mph.