Question

1. Fie trapezul dreptunghic ABCD cu AB║DC, m(∡A)=90° si AC⊥BC. Daca AB=12,3 cm si CD=7,5 cm, calculati aria trapezului.

Answer 1

Coboram,perpendiculara,din,C,pe,AB,si,notam,cu,M,piciorul,acesteia
In,tr.dr.ACB,aflam,inaltimea,CM,cu,t.inaltimii
CM²=AMxMB
AM=CD=7,5cm
MB=AB-AM=4,8cm
CM²=7,5x4,8=>CM²=36=>CM=6
Aria,trapezului=(B+b)xh/2=(12,3+7,5)6/2=>Aria=19,8x3=>Aria=59,4cm²