Ta có : $\widehat{IKA}$=$\widehat{BCA}$=$50^o$ (Đồng vị)
⇒ IK//BC
Ta lại có : $\begin{cases} IK//BC\\AK=KC \end{cases}$
⇒IK là đường trung bình của tam giác ABC
⇒ AI=BI=$10 cm^{}$
Vậy $x=10 cm^{}$
Đáp án:
Ta có: góc AKI = KCB ( = 50 độ ), mà đây là 2 góc đồng vị
=> KI // BC
Áp dụng định lý Ta-lét có:
$\frac{AK}{KC}$ = $\frac{AI}{IB}$
⇔$\frac{8}{8}$ = $\frac{x}{10}$
⇒ x = 10
Giải thích các bước giải:
Giúp mình bài 1 câu a và b thôi nhé, mình cảm ơn nhiều ‘“!
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