Question

$ABCD$ is a rhombus. If $\angle BCA={35}^o$, find $\angle ADC$.

Answer 1

Here in rhombus ABCD $\angle BCA={35}^o$

in $\Delta ABC$

$\angle BCA+\angle CBA+\angle BAC={100}^o$

$35+\angle CBA+35=100$

$\angle CBA=100-70$

$\angle CBA={110}^o$

We know

$\angle ABC+\angle ADC={100}^o$

${110}^o+\angle ADC=100$

$\angle ADC=100-110$

$\angle ADC=70$.