Đáp án:
Bài 1:
d’ = 9,6 cm; h’ = 12,8 cm
Bài 2:
d’ = 8,6 cm; h’ = 14,3 cm
Giải thích các bước giải:
Bài 1:
Ta có:
\(\begin{array}{l}
\dfrac{{AB}}{{A'B'}} = \dfrac{{OA}}{{OA'}} = \dfrac{{24}}{{OA'}}\\
\dfrac{{AB}}{{A'B'}} = \dfrac{{OI}}{{A'B'}} = \dfrac{{OF}}{{ - OA' + OF}} = \dfrac{{16}}{{16 - OA'}}\\
\Rightarrow \dfrac{{24}}{{OA'}} = \dfrac{{16}}{{16 - OA'}} \Rightarrow OA' = 9,6cm\\
\Rightarrow \dfrac{{AB}}{{A'B'}} = 2,5 \Rightarrow A'B' = 12,8cm
\end{array}\)
Bài 2:
Ta có:
\(\begin{array}{l}
\dfrac{{AB}}{{A'B'}} = \dfrac{{OA}}{{OA'}} = \dfrac{{15}}{{OA'}}\\
\dfrac{{AB}}{{A'B'}} = \dfrac{{OI}}{{A'B'}} = \dfrac{{OF}}{{ - OA' + OF}} = \dfrac{{20}}{{20 - OA'}}\\
\Rightarrow \dfrac{{15}}{{OA'}} = \dfrac{{20}}{{20 - OA'}} \Rightarrow OA' = 8,57cm\\
\Rightarrow \dfrac{{AB}}{{A'B'}} = 1,75 \Rightarrow A'B' = 14,3cm
\end{array}\)