Question

In the triangle

(i) If $\angle b={60}^{0}and\angle c={50}^0,find\angle a.$

(ii) If $\angle a={100}^{0}and\angle b={55}^0,find\angle c.$

(iii) If $\angle a={108}^{0}and\angle c={48}^0,find\angle b.$

Answer 1

In a triangle ($\Delta ABC$) sum of angles is $180°$, i.e. $\angle a+\angle b+\angle c=180°$.

$\left(1\right).\angle a=180°-\angle b-\angle c=180°-60°-50°=70°$

$\left(2\right).\angle c=180°-\angle a-\angle b=180°-100°-55°=25°$

$\left(3\right).\angle b=180°-\angle a-\angle c=180°-108°-48°=24°$