Question

In the figure given below, identify the right angled triangle.

• A. ΔBAC
• B. ΔAMB
• C. ΔANC
• D. ΔAMN

Answer 1

Answer: (A), (B), (D)

ΔAMN

In the given figure,
In ΔBAC
<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> ∠B = <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> ${70}^{\circ },$ ∠C = <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> ${20}^{\circ },$
∠BAC = ${180}^{\circ }-({70}^{\circ }+{20}^{\circ })={90}^{\circ }$
$\therefore$ <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> ΔBAC is a right angled triangle.

In ΔAMB
​​∠AMB = ${90}^{\circ }$
$\therefore$ <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> ΔAMB is a right angled triangle.

In ΔANC non of the angle is ${90}^{\circ }$.
So, ΔANC is not a right angled triangle.

In ΔAMN
∠AMN = <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> ${90}^{\circ },$
$\therefore$ <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> ΔAMN is a right angled triangle.

Hence, ΔBAC, ΔAMB, and ΔAMN are right angled triangles. <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}-->