find the unknowns in the following
Answers
Answer:
The value of variables is x = 20° & y = 50°.
Step-by-step-explanation:
NOTE: Refer to the attachment for the diagram.
We have given that,
□ ROSE is a parallelogram.
m∠RES = ( 3x - 10 )°
m∠OSE = ( 5x + 30 )°
m∠ROS = y°
We have to find the values of the variables i. e. x and y.
Now,
We know that,
Opposite angles of a parallelogram are congruent.
∴ m∠RES = m∠ROS
⇒ ( 3x - 10 )° = y°
⇒ 3x - 10 = y
⇒ 3x - y = 10 - - ( 1 )
Now, we know that,
Adjacent angles of a parallelogram are supplementary.
∴ m∠RES + m∠OSE = 180°
⇒ ( 3x - 10 )° + ( 5x + 30 )° = 180°
⇒ 3x - 10 + 5x + 30 = 180
⇒ 3x + 5x - 10 + 30 = 180
⇒ 8x + 20 = 180
⇒ 8x = 180 - 20
⇒ 8x = 160
⇒ x = 160 ÷ 8
⇒ x = 20°
By substituting x = 20 in equation ( 1 ), we get,
3x - y = 10 - - ( 1 )
⇒ 3 ( 20 ) - y = 10
⇒ 60 - y = 10
⇒ - y = 10 - 60
⇒ - y = - 50
∴ y = 50° - - ( 2 )
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Verification:
We know that,
m∠RES = m∠ROS
Now,
m∠RES = ( 3x - 10 )°
⇒ m∠RES = 3 ( 20 ) - 10
⇒ m∠RES = 60 - 10
⇒ m∠RES = 50° - - ( 3 )
Now,
m∠ROS = y°
⇒ m∠ROS = 50° - - [ From ( 2 ) ]
∴ m∠RES = m∠ROS
Hence verified!
Also, we know that,
m∠RES + m∠OSE = 180°
LHS = m∠RES + m∠OSE
⇒ LHS = 50° + ( 5x + 30 )° - - [ From ( 3 ) ]
⇒ LHS = 50 + 5 ( 20 ) + 30
⇒ LHS = 50 + 100 + 30
⇒ LHS = 150 + 30
⇒ LHS = 180
RHS = 180
∴ LHS = RHS
Hence verified!
⭐WHAT TO KNOW TO SOLVE THIS QUESTION:
(1) Opposite angles of a parallelogram are congruent.
(2) Adjacent sides of a parallelogram are supplementary.
⭐Given:
- Quadrilateral ROSE is a parallelogram.
- <RES=(3x-10°)
- <OSE=(5x+30°)
- <SOR=y
- <ERO=x
⭐To Find:
- <SOR=y=?
- <ERO=x=?
⭐Solution:
Here, Quadrilateral ROSE is a parallelogram.
Since,
We know that,
- Adjacent Sides of a parallelogram are supplementary.
: . <RES+<OSE=180°
: . (3x-10°) +(5x+30°) =180°
: . 3x-10+5x+30=180°
: . 3x+5x-10+30=180°
: . 8x+20=180°
: . 8x=180°-20
: . 8x=160
: . x=160/8
: . x=20
Therefore, <RES=(3x-10) =3×20-10=50..... (1)
<OSE=(5x+30) =5×20+30=130........ (2)
Again We know that,
- Opposite sides of a parallelogram are congruent.
: . <RES=<ROS=y
: . <ROS=y=50°........ [From (1) ]
and <OSE=<ORE=x
: . <ORE=x=130°........ [From (2) ]
Therefore Values of x and y are 130° and 50°respectively.
⭐VERIFICATION
We know that,
- Sum of all angles of a quadrilateral is 360°.
: . <RES+<ESO+<SOR+<ORE=360°
: . L. H. S=50°+130°+50°+130°=RH.S
Hence Verified that L. H. S =R.H.S