F.2 Plane Geometry

圖片參考：http://xs314.xs.to/xs314/07172/abc.png

a)
a = √(52 – 42)
= 3cm
b)
因為 PQRS 是一長方形所以對邊相等
b = a = 3cm
c = QR = 4cm

a^2+4^2=5^2
a^2=5^2-4^2
a=√(5^2-4^2 )
a=3


∵∆PQS(~=)∆RSQ (proved)
∴b=RS=3 (corr. sides(~=)∆s)
C=RQ=4 (corr. sides(~=)∆s)