Question

If two sides of a triangle are equal the angles opposite to them are also equal why?

• A. undefined
• B. undefined
• C. undefined
• D. undefined

Answer 1

We have $\Delta ABC$ with AB = AC
AD is the altitude
In $\Delta ADB$ & $\Delta ADC$
AB = AC (Given)
AD = AD (Common)
$\angle ADB=\angle ADC={90}^{\circ }$
$\therefore$ By RHS congiuency condition
$\Delta ADB\cong \Delta ADC\Rightarrow \angle ABC=\angle ACB\left(CPCT\right)$