MCQ 511 Mark
Assertion and Reason Type $\text{MCQ}$
Assertion : If three angles of a quadrilateral are $130^\circ , 70^\circ $ and $60^\circ ,$ then the fourth angles is $100^\circ .$
Reason : The sum of all the angle of a quadrilateral is $360^\circ .$
Assertion : If three angles of a quadrilateral are $130^\circ , 70^\circ $ and $60^\circ ,$ then the fourth angles is $100^\circ .$
Reason : The sum of all the angle of a quadrilateral is $360^\circ .$
- ✓Both Assertion $(A)$ and Reason $(R)$ are true and Reason is a correct explanation of Assertion $(A)$.
- BBoth Assertion $(A)$ and Reason $(R)$ are true but Reason is not a correct explanation of Assertio $(A)$.
- CAssertion $(A)$ is true and Reason $(R)$ is false.
- DAssertion $(A)$ is false and Reason $(R)$ is true.
Answer
View full question & answer→Correct option: A.
Both Assertion $(A)$ and Reason $(R)$ are true and Reason is a correct explanation of Assertion $(A)$.
Let the fourth angle be $x.$
We know that the sum of all the angles of a quadrilateral is $360^\circ .$
$\Rightarrow 130^\circ + 70^\circ + 60^\circ + x = 360^\circ $
$\Rightarrow x = 100^\circ $
So, the fourth angles is $100^\circ .$
Thus, the Assertion $(A)$ is true The reason $(R)$ is alos true and is the correct explanation for the Assertion $(A).$
We know that the sum of all the angles of a quadrilateral is $360^\circ .$
$\Rightarrow 130^\circ + 70^\circ + 60^\circ + x = 360^\circ $
$\Rightarrow x = 100^\circ $
So, the fourth angles is $100^\circ .$
Thus, the Assertion $(A)$ is true The reason $(R)$ is alos true and is the correct explanation for the Assertion $(A).$