Question

有关于勾股定理滴...如图,在△ABC中,∠ACB=90°,AC=2.1cm,BC=2.8cm,CD⊥AB,垂足为D.求

Answer 1

如图,在△ABC中,∠ACB=90°,AC=2.1cm,BC=2.8cm,CD⊥AB,垂足为D.求：

1.△ABC的面积S=AC*BC/2

=2.1*2.8/2

=2.94平方厘米

2.斜边AB的长=(AC^2+BC^2)^0.5

=(2.1^2+2.8^2)^0.5

=3.5厘米

3.斜边AB上的高CD=2*S/AB

=2*2.94/3.5

=1.68厘米