Question

In trapezul ABCD ,AD||BC ,AD=30 cm ,DC=20 cm , AB=15cm,BC=5cm . Sa se afle lungimea diagonalei AC.

Answer 1

Duci diagonala si se formează ∆ACD .
p.p ( presupui) ∆ADC ,m(<D)= 90°
AC^2 ( AC la puterea2) = AD^2 + DC^2
AC^2 = 30^2 + 20^2
AC^2 = 900+400
AC^2= 1300
AC= √1300
AC= 36,05 cm .