Math, asked by arnadsasmal980, 2 months ago

in ABCD, Side BC < Side AD side BC side AD and if side BA side CD
Then prove that: ABCD DCB​

Answers

Answered by AFAC
5

Step-by-step explanation:

Given: side BC < side AD, side BC || side AD, side BA = side CD

To prove: ∠ABC ≅ ∠DCB Construction: Draw seg BP ⊥ side AD, A – P – D seg CQ ⊥ side AD, A – Q – D

Proof:

In ∆BPA and ∆CQD,

∠BPA ≅ ∠CQB [Each angle is of measure 90°]

Hypotenuse BA ≅ Hypotenuse CD [Given]

seg BP ≅ seg CQ [Perpendicular distance between two parallel lines]

∴ ∆BPA ≅ ∆CQD [Hypotenuse side test]

∴ ∠BAP ≅ ∠CDQ [c. a. c. t.]

∴ ∠A = ∠D ….(i)

Now, side BC || side AD and side AB is their transversal. [Given]

∴ ∠A + ∠B = 180°…..(ii) [Interior angles] Also, side BC || side AD and side CD is their transversal. [Given]

∴ ∠C + ∠D = 180° …..(iii) [Interior angles]

∴ ∠A + ∠B = ∠C + ∠D [From (ii) and (iii)]

∴ ∠A + ∠B = ∠C + ∠A [From (i)]

∴ ∠B = ∠C

∴ ∠ABC ≅ ∠DCB

Answered by AFAC
2

Step-by-step explanation:

Given: side BC < side AD, side BC || side AD, side BA = side CD

To prove: ∠ABC ≅ ∠DCB Construction: Draw seg BP ⊥ side AD, A – P – D seg CQ ⊥ side AD, A – Q – D

Proof:

In ∆BPA and ∆CQD,

∠BPA ≅ ∠CQB [Each angle is of measure 90°]

Hypotenuse BA ≅ Hypotenuse CD [Given]

seg BP ≅ seg CQ [Perpendicular distance between two parallel lines]

∴ ∆BPA ≅ ∆CQD [Hypotenuse side test]

∴ ∠BAP ≅ ∠CDQ [c. a. c. t.]

∴ ∠A = ∠D ….(i)

Now, side BC || side AD and side AB is their transversal. [Given]

∴ ∠A + ∠B = 180°…..(ii) [Interior angles] Also, side BC || side AD and side CD is their transversal. [Given]

∴ ∠C + ∠D = 180° …..(iii) [Interior angles]

∴ ∠A + ∠B = ∠C + ∠D [From (ii) and (iii)]

∴ ∠A + ∠B = ∠C + ∠A [From (i)]

∴ ∠B = ∠C

∴ ∠ABC ≅ ∠DCB

Answered by AFAC
2

Step-by-step explanation:

Given: side BC < side AD, side BC || side AD, side BA = side CD

To prove: ∠ABC ≅ ∠DCB Construction: Draw seg BP ⊥ side AD, A – P – D seg CQ ⊥ side AD, A – Q – D

Proof:

In ∆BPA and ∆CQD,

∠BPA ≅ ∠CQB [Each angle is of measure 90°]

Hypotenuse BA ≅ Hypotenuse CD [Given]

seg BP ≅ seg CQ [Perpendicular distance between two parallel lines]

∴ ∆BPA ≅ ∆CQD [Hypotenuse side test]

∴ ∠BAP ≅ ∠CDQ [c. a. c. t.]

∴ ∠A = ∠D ….(i)

Now, side BC || side AD and side AB is their transversal. [Given]

∴ ∠A + ∠B = 180°…..(ii) [Interior angles] Also, side BC || side AD and side CD is their transversal. [Given]

∴ ∠C + ∠D = 180° …..(iii) [Interior angles]

∴ ∠A + ∠B = ∠C + ∠D [From (ii) and (iii)]

∴ ∠A + ∠B = ∠C + ∠A [From (i)]

∴ ∠B = ∠C

∴ ∠ABC ≅ ∠DCB

Answered by AFAC
2

Step-by-step explanation:

Given: side BC < side AD, side BC || side AD, side BA = side CD

To prove: ∠ABC ≅ ∠DCB Construction: Draw seg BP ⊥ side AD, A – P – D seg CQ ⊥ side AD, A – Q – D

Proof:

In ∆BPA and ∆CQD,

∠BPA ≅ ∠CQB [Each angle is of measure 90°]

Hypotenuse BA ≅ Hypotenuse CD [Given]

seg BP ≅ seg CQ [Perpendicular distance between two parallel lines]

∴ ∆BPA ≅ ∆CQD [Hypotenuse side test]

∴ ∠BAP ≅ ∠CDQ [c. a. c. t.]

∴ ∠A = ∠D ….(i)

Now, side BC || side AD and side AB is their transversal. [Given]

∴ ∠A + ∠B = 180°…..(ii) [Interior angles] Also, side BC || side AD and side CD is their transversal. [Given]

∴ ∠C + ∠D = 180° …..(iii) [Interior angles]

∴ ∠A + ∠B = ∠C + ∠D [From (ii) and (iii)]

∴ ∠A + ∠B = ∠C + ∠A [From (i)]

∴ ∠B = ∠C

∴ ∠ABC ≅ ∠DCB

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