Mathematics
Assertion (A) : If one angle of a parallelogram measures 90°, the parallelogram is rectangle.
Reason (R) : If each interior angle of parallelogram is 90°, then all sides of it are equal.
Both A and R are correct, and R is the correct explanation for A.
Both A and R are correct, and R is not the correct explanation for A.
Statement 1 is true, and statement 2 is false.
Statement 1 is false, and statement 2 is true.
Answer
If one angle is 90°, the opposite angle is also 90° as opposite angles of a parallelogram are equal.
If one angle is 90°, the adjacent angle is 180° - 90° = 90°, as the sum of adjacent angles in a rectangle is 180°.
Thus, all angles of parallelogram are 90° if one angle is 90°.
Therefore, the parallelogram is a rectangle.
So, assertion (A) is true.
A parallelogram with all interior angles equal to 90° is a rectangle, but not necessarily a square. Therefore, all sides are not necessarily equal.
So, reason (R) is false.
∴ A is true, but R is false.
Hence, option 3 is the correct option.
Related Questions
Assertion (A) : In a parallelogram, the bisectors of any two pair of adjacent angles meet at right angle.
Reason (R) : In a parallelogram opposite angles are equal.
Both A and R are correct, and R is the correct explanation for A.
Both A and R are correct, and R is not the correct explanation for A.
Statement 1 is true, and statement 2 is false.
Statement 1 is false, and statement 2 is true.
Assertion (A) : One of the diagonals of rhombus is equals to one of its side. The angles of a rhombus are 60°, 120°, 60°, 120°.
Reason (R) : All the sides of a rhombus are equal.
Both A and R are correct, and R is the correct explanation for A.
Both A and R are correct, and R is not the correct explanation for A.
Statement 1 is true, and statement 2 is false.
Statement 1 is false, and statement 2 is true.
Assertion (A) : The adjacent angles of a parallelograms are in ratio 2 : 3 the remaining angles are 78° and 102°.
Reason (R) : Opposite angles of a parallelogram are equal.
Both A and R are correct, and R is the correct explanation for A.
Both A and R are correct, and R is not the correct explanation for A.
Statement 1 is true, and statement 2 is false.
Statement 1 is false, and statement 2 is true.
The adjacent sides of a parallelogram are in the ratio 5 : 4. If the perimeter of the parallelogram is 108 cm, find the length of its sides.