HARD
9th Manipur Board
IMPORTANT
Earn 100

Prove that lines which are perpendicular to the same line are parallel to one another.

Important Questions on Lines and Angles

HARD
9th Manipur Board
IMPORTANT
Mathematics for Class 9>Chapter 6 - Lines and Angles>EXERCISE 6.3>Q 6
Two unequal angles of a parallelogram are in the ratio 4:5. Find all the angles of the parallelogram.
HARD
9th Manipur Board
IMPORTANT
Mathematics for Class 9>Chapter 6 - Lines and Angles>EXERCISE 6.3>Q 7
Prove that if two arms of an angle are perpendicular to the two arms of another angle, then the angles are either equal or supplementary.
HARD
9th Manipur Board
IMPORTANT
Mathematics for Class 9>Chapter 6 - Lines and Angles>EXERCISE 6.3>Q 8
If one angle of a parallelogram is 60°, find the other angles.
EASY
9th Manipur Board
IMPORTANT
Mathematics for Class 9>Chapter 6 - Lines and Angles>EXERCISE 6.4>Q 1
If the angles of a triangle are in ratio 1:2:6, determine the three angles.
EASY
9th Manipur Board
IMPORTANT
Mathematics for Class 9>Chapter 6 - Lines and Angles>EXERCISE 6.4>Q 2
If one angle of a triangle is equal to the sum of the other two, show that the triangle is a right triangle.
EASY
9th Manipur Board
IMPORTANT
Mathematics for Class 9>Chapter 6 - Lines and Angles>EXERCISE 6.4>Q 3

If the bisectors of the base angles of a triangle enclose an angle of 135°, prove that the triangle is a right triangle.

MEDIUM
9th Manipur Board
IMPORTANT
Mathematics for Class 9>Chapter 6 - Lines and Angles>EXERCISE 6.4>Q 4
In any regular polygon of n sides, prove that each of its angles measures n-2n×180°.
MEDIUM
9th Manipur Board
IMPORTANT
Mathematics for Class 9>Chapter 6 - Lines and Angles>EXERCISE 6.4>Q 5
The sides AB and AC of the ∆ABC are produced to P and Q respectively. The bisectors of ∠PBC and ∠QCB intersects at O. Prove that ∠BOC=90°-12∠BAC.