Answer:

Step-by-step explanation:
The total surface area of a cone is given by :

Put r = 2r and l = 2l in the above formula

Hence, the total surface area of the cone is
.
Answer:

Step by step
Remember, a reference angle is a positive acute angle that represents an angle θ of any measurement.
a)
, then its reference angle is 
b)
is in the second cuadrant, then its reference angle is 
c)
, then it is in the first cuadrant and the reference angle is
.
d)
and it is in the third cuadrant, then its reference angle is 
The two planes are flying on the two legs of a right triangle.
The straight distance between them is the hypotenuse of the triangle.
Since the speeds are in mph, let's work the time in hours.
Call the time 'H' that we're looking for.
It's the number of hours after they both take off that they're 650 miles apart.
After 'H' hours, the first plane has gone 500H miles north.
After 'H' hours, the second plane has gone 1200H miles east.
After 'H' hours, they are 650 miles apart.
Do you remember this for a right triangle ? ==> A² + B² = C²
(500H)² + (1200H)² = (650)²
250,000H² + 1,440,000H² = 422,500
1,690,000 H² = 422,500
H² = (422,500) / (1,690,000) = 0.25
H = √0.25 = 1/2 hour = 30 minutes
Answer:
7 rides
Step-by-step explanation:
So you start off with $21.50. Subtract $4 from 21.50 and you'll end up with $17.50. Now divide $17.50 with the price of each ride which is $2.50 and you end up with 7. You are able to go on 7 rides.