please answer this question
Answers
Answer:
1) 120°
2) 60°
3) 45°
4) 35°
5)40°
8) 25°
9)10
1.a
2.b
3.d
4.d
5.a
6.d
7.c
8.d
9.a
10.b
Solutions :-
1)
Given that
l || m
t is a transversal
We have ∠z and 60° are the interior angles on the same side to the transversal .
Therefore, ∠z and 60° are Supplementary angles.
=> ∠z+60° = 180°
=> ∠z = 180°-60°
=> ∠z = 120°
2)
Given that
l || m
t is a transversal
We have ∠x and 60° are the alternative interior angles.
Therefore, ∠x and 60° are equal.
=> ∠x = 60°
3)
Let the angle be X°
The complement of X° = 90°-X°
Given that
The angle = 4 times to its complement
=> X° = 4(90°-X°)
=> X° = 360°-4X°
=> X°+4X° = 360°
=> 5X° = 360°
=> X° = 360°/5
=> X° = 72°
The angle is 72°
4)
Given that
125° is the exterior angle of the triangle
x° and 90° are the opposite interior angles of 125°
=> x°+90° = 125°
=> x° = 125°-90°
=> x° = 35°
5)
Given that
In ∆XYZ, XY = YZ
=> ∠X = ∠Z
Since, The angles opposite to equal sides are equal.
Let ∠X = ∠Z = A°
Given that ∠Y = 100°
We know that
The sum of the three interior angles in a triangle is 180°
=> ∠X + ∠Y + ∠Z = 180°
=> A°+100°+A° = 180°
=> 2A° +100° = 180°
=> 2A° = 180°-100°
=> 2A° = 80°
=> A° = 80°/2
=> A° = 40°
Therefore, ∠X = ∠Z = 40°
∠Z = 40°
6)
Given that
In ∆ PQR, ∠P = 90° , ∠Q = 30° and ∠R = x°
We know that
The sum of the three interior angles in a triangle is 180°
=> ∠P + ∠Q + ∠R = 180°
=> 90°+30°+x° = 180°
=> 120°+x° = 180°
=> x° = 180°-120°
=> x° = 60°
7)
In ∆ ADC and ∆ ABC
∠CAD = ∠CAB
AC = AC
∠ACD = ∠ACB
By ASA Congruency rule ,∆ ACD and ∆ABC are Congruent triangles.
8)
Given that
Total number of children in a class = 40
Number of boys in the class = 10
The percentage of boys =
(No. of boys / Total no.of children)×100
= (10/40)×100
=> 100/4
= 25
The percentage of boys in the class = 25%
9)
Given that
Total number of children in a class = 40
Number of children like foot ball
= 25% of total number of children
= (25/100)×40
= (1/4)×40
= 40/4
= 10
No. of children who likes to play foot ball is 10
10)
Given that
The Cost Price of the coat = Rs. 7600
Sales tax on it = 4%
= 4% of 7600
= 4% × 7600
= (4/100)×7600
= 4×76
= Rs. 304