Plz explain the questions along with the answers.......
Answers
Question # 35
Answer:
K = 2
Step-by-step explanation:
Given:-
- ABCD is a parallelogram
- ∠DAB = 60°
- AP and BP bisect ∠DAB and ∠ABC respectively
To find:-
- Value of K when
Solution:-
Since ABCD is a parallelogram, we have,
∠DAB+∠ABC=180° [Adjacent angles of a parallelogram are supplementary]
→60° + ∠ABC = 180°
→∠ABC = 180° - 60°
→∠ABC = 120°
Now,
AP and BP bisect ∠DAB and ∠ABC respectively
→ ∠PAD = ∠PAB = ∠DAB / 2 and ∠PBC = ∠ABP = ∠ABC / 2
→∠PAD = ∠PAB = 60° / 2 and ∠PBC = ∠ABP = 120° / 2
→∠PAD = ∠PAB = 30° and ∠PBC = ∠ABP = 60°
Since ABCD is a parallelogram, we have
AB ║ CD
→∠APD = ∠PAB = 30°, [Alternate interior angles]
and ∠BPC = ∠ABP = 60° [Alternate interior angles]
But, ∠PAD = ∠PAB = 30° and ∠PBC = ∠ABP = 60°
→∠APD = ∠PAD = 30° and ∠BPC = ∠PBC = 60°
In ΔAPD, we have
∠APD = ∠PAD = 30°
→PD = AD
In ΔBPC, we have
∠BPC = ∠PBC = 60°,
and also
∠BCP = ∠DAB = 60° [Opposite angles of a parallelogram]
→ΔBPC is equilateral
→BC = PC = BP
Now,
PD = AD and BC = PC = BP
but, AD = BC [Opposite sides of a parallelogram]
→PD = AD = BC = PC = BP
→PD = PC
Now,
PD + PC = CD
→2PC = CD
→
but,
→ K = 2
Question # 31
Answer:
0
Step-by-step explanation:
Given:-
To find:-
- Value of x + y + z
Solution:-
→ y = , and
z =
x + y + z
= x + +
= + +
=
=
= x[b² + bc - 2ab - bc - c² + 2ac + c² + ac - 2bc - ac - a² + 2ab + a² + ab - 2ac - ab - b² + 2bc] / (b - c)(b + c - 2a)
= x[0] / (b - c)(b + c - 2a)
= 0