0.8-0.3 = 0.5 hours

2.4 * 0.5 = 0.3 times

x=4

Go downhill at a speed of 4 kilometers per hour.

Bottom circumference = height = height = 62.8cm.

If π=3. 14

The base diameter is 62.8/3. 14=20cm.

S total =(20/2)？ * 3. 14+62.8 * 62.8 = 3943.84+3 14 = 4257.84cm？

I hope it will help you, please adopt it as a satisfactory answer in time.

It is not easy to answer questions, please understand, thank you.

Your adoption is my motivation to move forward ~ ~

~ If you have a new question, you can send it in the form of a question, or you can ask me for help or send a question link address at the place where you ask it. Thank you.