Explicație pas cu pas:
a) ABC triunghi dreptunghic => T.Pitagora AC²=AB²+BC² => AC²=108+324 => AC²=432=> AC=12V3 cm
b)Cum DP _|_AC => mPDC+mDCP=90° dar cum mPDC+mDMC=90 => mDCP=mDMC
Deci mDCP=mDMC si mDCM=mD=90° => (U.U) Triunghi CMD~DCA deci CM/6V3=6V3/18 => CM/6V3=V3/3 => CM=6cm
c)cum mDCP+mCDP=90 dar mDCP+mDAC=90 => mCDP=mDAC deci triunghi DPC~ADC => DP/AD=PC/DC=DC/AC=k => 1/2=k
A CDP/A ADC=k²=1/4 => A ADC=A ABC= 4A CDP
Deci x/100 × A ABC = A DPC => x/100 × 4A DPC= A DPC => x/25 =1 => x=25 deci ADPC =25% A ABC
