¡÷ABC is an isosceles right triangle, AB=a,
AC=BC= 2 2 a£¬
So S ¡÷ABC = 1 2 AC? BC= 1 2 ¡Á 2 a 2£¿ 2 a 2 = a 2 4£¬
The area of the middle
What is the best eight-character pattern?
First, the Japanese branch is a favorite god, and the pattern of t