Fie paralelipipedul dreptunghic abcda'b'c'd'. demonstrati ca ( c'db ) paralel ( ad'b' )

cu desen va rog.

!! 10 ! a westbound jet leaves central airport traveling 635 miles per hour. at the same time, an eastbound plane departs at 325 miles per hour. in how many hours will the planes be 1900 miles apart?

Find two numbers if their sum is 91 and the ratio is 6: 7?

If tan2a=cot(a+60), find the value of a, where 2a is an acute angle