Question

己知如图在梯形ABCD中AB平行CD,角A=60度角B=45度DC=2,AD=4求梯形面积

Answer 1

作DF⊥AB,交AB于F点,

在△ADF中,DF=2√3

AB=2+2+ 2√3=4 +2√3

S梯形=(AB+DC)XDF/2

= (6+ 2√3)2√3/2

=6 √3+6