Cho tam giác ABC. Kẻ trung tuyến AM a. Chứng minh: tam giác ABM= tam giác ACM
b. Từ M kẻ MH vuông góc AB( K thuộc AC). Chứng minh: AM là đướng trung trực của HK
c. Biết AB= 10 cm; BC= 16 cm. Tính AM
d. Vẽ 2 đường trung tuyến BI và CN. Chứng minh 3/4(AB+AC+BC)

Use the information given below, to compare the cost of operating two different vehicles for one month (4 weeks) you are considering two different cars. you drive to work, a 20 mile round trip, five days a week. gasoline costs you $1.50 per gallon car agets 28 miles per gallon, would have $300 a year in maintenance costs, and would cost you $1,500 per year to insure car b gets 19 miles per gallon, would have $500 a year in maintenance costs, and would cost you $1,000 per year to insure costs car a car b gas cost per month insurance cost per month maintenance cost per month $ total cost per month