Find angle x

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In  ∆ABC,

AB = AC     (Given)

 

Therefore,

∠C = ∠B         (Angles opposite to equal sides are equal)

40° = x

x = 40°   

 

Find angle x

Isosceles Triangle - Questions - Part 2

In  ∆PQR,

PQ = QR          (Given)

 

Therefore,

∠R = ∠P           (Angles opposite to equal sides are equal)

45° = ∠P

∠P = 45°

 

Now, by Angle sum property, 

∠P + ∠Q + ∠R = 180°

45° + x + 45° = 180°

x + 90° = 180°

x = 180° − 90°    

x = 90 °

 

Find angle x

Isosceles Triangle - Questions - Part 3

In  ∆XYZ,

XZ = ZY         (Given)

 

Therefore,

∠Y = ∠X      (Angles opposite to equal sides are equal)

x = 50°

 

Find angle x

Isosceles Triangle - Questions - Part 4

In  ∆ABC,

AB = CA       (Given)

 

Therefore,

∠C = ∠B      (Angles opposite to equal sides are equal)

∠C  = x

 

Now, By angle sum property,

  ∠A + ∠B +∠C = 180°    

   100° + x + x = 180°

   100° + 2x = 180°

  2x = 180° − 100°

  2x = 80°

  x = 80° /2

  x = 40°

 

Find angle x

Isosceles Triangle - Questions - Part 5

In  ∆PQR,

QR = PQ      (Given)

 

Therefore,

∠P = ∠R    (Angles opposite to equal sides are equal)

x  = ∠R

∠R = x

 

Now, by angle sum property, 

∠P + ∠Q + ∠R = 180°  

x + 90° + x = 180°

90° + 2x = 180°

2x = 180° − 90°

2x = 90°

x = (90°)/2

x = 45°  

 

Find angle x

Isosceles Triangle - Questions - Part 6

In  ∆XYZ,

XY = YZ          (Given)

 

Therefore,

∠Z = ∠X         (Angles opposite to equal sides are equal)

x  = ∠X

∠X = x

 

Now, by angle sum property, 

∠X + ∠Y + ∠Z = 180°  

x + 40° + x = 180°

40° + 2x = 180°

2x = 180° − 40°

2x = 140°

x = (140°)/2

x = 70°  

 

Find angle x

  Isosceles Triangle - Questions - Part 7

In  ∆PQR,

PQ = PR      (Given)

 

Therefore,

∠PRQ = ∠Q       (Angles opposite to equal sides are equal)

∠PRQ = x  

 

Now,

∠PRQ + ∠PRS = 180°      (Linear pair)

x + 120° = 180°

x = 180° − 120°

x = 60 °   

 

Find angle x

Isosceles Triangle - Questions - Part 8

In  ∆PQR,

PR = PQ       (Given)

 

Therefore,

∠Q = ∠R      (Angles opposite to equal sides are equal)

∠Q = x

 

We know that,

Exterior angle is equal to sum of interior opposite angles

∠SPR = ∠Q + ∠R

110° = x + x

110° = 2x

(110°)/2 = x

55° = x

x = 55° 

 

Find angle x

Isosceles Triangle - Questions - Part 9

Here

∠MYN  = ∠ZYX      (Vertically opposite angles)

30°  = ∠ZYX

∠ZYX = 30° 

 

In ∆XYZ,

YZ = ZX           (Given)

 

Therefore,

30°  = ∠ZYX         (Angles opposite to equal sides are equal)

∠X = ∠ZYX

x = 30° 

 

Find angle x and y

Isosceles Triangle - Questions - Part 10

In  ∆ABC,

AC = AB                  (Given)

 

Therefore,

∠B = ∠ACB           (Angles opposite to equal sides are equal)

y = ∠ACB  

∠ACB = y

 

Now,

∠ACB + ∠ACD = 180°             (Linear pair)

y + 120° = 180° 

y = 180° − 120°  

y = 60°

 

We know that,

Exterior angle is equal to sum of interior opposite angles.

  ∠ACD = ∠A + ∠B

  120 ° = x + y

  120 ° = x + 60°

  120 ° − 60° = x

  60° = x

  x = 60°   

 

Find angle x and y

Isosceles Triangle - Questions - Part 11

In  ∆PQR,

            QR = PR                        (Given)

 

Therefore,

∠QPR = ∠Q                (Angles opposite to equal sides are equal)

∠QPR = x

 

Now,

In Δ PQR

By Angle sum property

∠ QPR + ∠ Q + ∠ R = 180°

x + x + 90° = 180°

2x + 90° = 180°

2x = 180° – 90°

2x = 90°

x = (90°)/2

x = 45°

 

Also,

Exterior angle is sum of interior opposite angles

y = x + ∠ R

 

y = 45° + 90°

y = 135°

 

Find angle x and y

Isosceles Triangle - Questions - Part 12

Here,

  ∠JIK = ∠MIN        (Vertically opposite angle)

  ∠JIK = 92°   

 

In ∆IJK,

  IJ = IK                   (Given)

 

Therefore,

  ∠IKJ = ∠IJK        (Angles opposite to equal sides are equal)

  ∠IKJ = x

 

Now, By angle sum property,

 ∠IJK + ∠JKI + ∠KIJ = 180°

  x + x + 92° = 180°

  2x + 92° = 180°

  2x = 180° − 92°

  2x = 88°

  x = (88°)/2

  x = 44°   

 

Hence,

  IKJ = x

  ∠IKJ = 44°

 

Now,

  ∠IJK + ∠IKL = 180°       (Linear pair)

  44° + y = 180°

  y = 180° − 44° 

  y = 136°

 

x = 44° and y = 136° 

 

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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.