Ducem BE⊥ CD BE inaltimea trapezului CE= CD - AB CE = 11-5 = 6
In Δ BEC cu ∡E=90° BC=10 CE = 6 aplic TP
BE² = BC² - CE²
BE² = 100 - 36
BE² = 64
BE = √64
BE = 8
A trapez = (B+b)·h/2
A tr = (5+11)· 8/2
Atr = 16·4
Atr· = 64 cm²
P tr = AB+BC+CD+AD = 5+10+11+8 = 34 cm (AD= BE)