BCDE is a rectangle, Z
/_OCD = 47° Find angles x, y and z. If BD = 5a - 3 and EC = a + 5. Find a, length of EC.
STEP BY STEP
PLEASE ANSWER THE QUESTION IF YOU KNOW THE ANSWER IF YOUR ANSWER IS IRRILATIVE I'LL REPORT THAT ANSWER
IF YOUR ANSWER IS RIGHT THAN I'LL GIVE YOU 7 THANKS
Answers
Hope u find this helpful....
If any query message me!!!
Given data :
- BCDE is a rectangle.
- ∠OCD = 47°
- BD = 5a - 3 and EC = a + 5
To find : Value of ‘a’ and EC and angles x, y and z.
Solution :
Here we know, from figure
→ ∠CDO or∠CDB = ∠ x
→ ∠EBD = ∠ y
→ ∠COB = ∠ z
According to figure,
→∠ECD or ∠OCD = 47°
Here, we know that the properties of the rectangle : The opposite sides are parallel and of equal length. Hence
→ ∠ECD = ∠CEB { Alternate angles }
→ ∠ECD = ∠CEB = 47°
Properties of the rectangle :
- The diagonals of a rectangle are of equal length.
Here from, property of rectangle,
→ BD = EC ......( 1 )
Properties of the rectangle :
The diagonals of a rectangle are bisect each other. Hence, ‘O’ is the mid point of diagonal BD and diagonal EC.
Now,
→ BD = BO + OD ......( 2 )
→ EC = EO + OC ......( 3 )
According to property of diagonal of rectangle,
→ BO = OD
→ EO = OC
Hence, eq. ( 2 ) become's
→ BD = OD + OD
→ BD = 2 OD ......( 4 )
and eq. ( 3 ) become's
→ EC = OC + OC
→ EC = 2 OC ......( 5 )
Now, from eq. ( 4 ) & eq. ( 5 )
∴ eq. ( 1 ) become's,
→ BD = EC
→ 2 OD = 2 OC
{ divide both side by 2 }
→ OD = OC {since, ‘O’ is the mid point of diagonal BD and diagonal EC}
→ ∠CDO = ∠OCD {angle opposite to equal sides are equal}
Similarly,
→ ∠CBD =∠BCO ......( 6 )
{angle opposite to equal sides are equal}
Hence,
→ ∠CDO = ∠OCD = 47°
∴ ∠CDO = 47°
∴ ∠x = 47°
Now, we know the opposite sides of rectangle are equal and parallel. Hence,
→ ∠CDO or∠CDB = ∠EBD {Alternate angle's}
→ ∠x = ∠y
∴ ∠x = ∠y = 47°
∴ ∠y = 47°
From the properties of the rectangle :
- Each vertex has angle equal to 90 degrees.
- All the interior angles of a rectangle are equal to 90 degrees.
Hence,
→∠EBD + ∠CBD = 90°
→ y + ∠CBD = 90°
→ 47° + ∠CBD = 90°
→ ∠CBD = 90° - 47°
→ ∠CBD = 43°
{ Note : ∠CBD or ∠CBO }
Now, from eq. ( 6 )
→ ∠CBD =∠BCO
∴ ∠BCO = 43°
Take Δ BOC from figure,
We know that, sum of the angles of the triangle are equal to 180°. Hence,
→∠CBO + ∠COB + ∠BCO = 180°
→ 43° + ∠COB + 43° = 180°
→ ∠COB + 86° = 180°
→ ∠COB = 180° - 86°
→ ∠COB = 94°
Here we know, ∠COB = z
∴ ∠ z = 94°
Now, from eq. ( 1 )
→ BD = EC
{from given}
→ 5a - 3 = a + 5
→ 5a - a = 5 + 3
→ 4a = 8
→ a = 8/4
→ a = 2
Hence,
→ EC = a + 5
→ EC = 2 + 5
→ EC = 7
Answer : Hence, value of ‘a’ is 2 and value of EC is 7 and also ∠x is 47°,∠y is 47° and ∠ z is 94°.