ridge tent       
noun [ C ] uk/ˈrɪdʒ ˌtent/ us/ˈrɪdʒ ˌtent/
 三角帐篷
a type of tent that has a pole along the top where two sloping sides meet
  Ridge tents are the traditional, classic, triangular-shaped tents. 三角帐篷是传统的经典的三角形的帐篷。 
 - More examples
 - The company attracted headlines for selling a ridge tent at the ridiculously low price of £7.49.
 - This two-person ridge tent has sewn-in guy ropes and weighs 4.2kg.
 - "Morning," shouted John, poking his head out of the flap of his ridge tent.
 - Some ridge tent poles have springs to snap the pole sections together.