c. Complementary angles
d. Supplementary angles
e. Linear pair of angle
63. Angles opposite to equal sides of an isosceles triangle are equal, prove it.
64. ABC is right angled triangle in which ∠A = 90
0
and AB = AC find ∠B and ∠C.
65. Write the angle sum property of the triangle and prove it.
66. Write the exterior angle property of the triangle and prove it.
67. Show that the angles of an equilateral triangle is 60
0
.
68. In the given figure, if PQ∥RS, ∠MXQ = 135
0
, ∠MYR = 40
0
, find ∠XMY.
69. If the bisector of the exterior angle of a ABC is parallel to the side AB, then prove that
∆ ∆
ABC is an isosceles triangle.
70. If a transversal intersects two parallel lines, prove that the bisectors of the interior angles
on the same side of the transversal intersect each other at right angle.
71. It is given ∠XYZ = 64 and XY is produced to point P. Draw a figure from the given
information. If a ray YQ bisects ∠ZYP find ∠XYQ and reflex ∠QYP.
72. Can a triangle have two obtuse angles ? Give reason for your answer.
73. Prove that the sum of the angles of a triangle is 180
0
.
74. Assertion: If angles ‘a’ and ‘b’ form a linear pair of angles and a = 40
0
, then b = 150
0
.
Reason: Sum of linear pair of angles is always 180
0
.
a. Both assertion (A) and reason (R) are true and (R) is the correct explanation of
assertion (A).
b. Both assertion (A) and reason (R) are true and (R) is not the correct explanation
of assertion (A).
c. Assertion (A) is true but reason (R) is false.
d. Assertion (A) is false but reason (R) is true.
75. Assertion(A): If two interior angles of the same side of a transversal intersecting two
parallel lines are in the ratio 5:4, then the greater of the two angles is 100
0
.
Reason(R): If a transversal intersects two parallel lines, then the sum of the interior
angles on the same side of the transversal is 180
0
.
a. Both assertion (A) and reason (R) are true and (R) is the correct explanation of
assertion (A).
b. Both assertion (A) and reason (R) are true and (R) is not the correct explanation
of assertion (A).
c. Assertion (A) is true but reason (R) is false.