English

In the Following Diagrams Abcd is a Square and Apb is an Equilateral Triangle in Each Case Prove That: δApd≅ δBpc Find the Angles of δDpc - Mathematics

Advertisements
Advertisements

Question

In the following diagram, ABCD is a square and APB is an equilateral triangle.

(i) Prove that: ΔAPD≅ ΔBPC
(ii) Find the angles of ΔDPC.

Sum

Solution

Given: ABCD is a Square and ΔAPB is an equilateral triangle.
We need to

(i) Prove that: ΔAPD≅ ΔBPC

(ii) Find the angles of ΔDPC

Proof:

Since AB side is present in both square & equilateral triangle

AP = PB = AB =AD = CD = BC

(i) In ΔBPC,

BP  = BC

∴ ∠BPC = ∠PCB

∠BPC + ∠PCB + 30° = 180°

∠BPC  + ∠BPC  = 150°

2∠BPC = ` (150°)/2 = 75°`

∴ ∠BPC = ∠PCB = 75°

∠ADP = ∠DPA = 75°    ...[C.P.C.T.C]

(ii) In DPC

∠DCP =  90° - 75° =  15° 

∠PDC = 90° - 75° =  15° 

∠DPC = 180° - (15° + 15°)

∠DPC = 150°

shaalaa.com
  Is there an error in this question or solution?
Chapter 9: Triangles [Congruency in Triangles] - Exercise 9 (B) [Page 125]

APPEARS IN

Selina Concise Mathematics [English] Class 9 ICSE
Chapter 9 Triangles [Congruency in Triangles]
Exercise 9 (B) | Q 2.1 | Page 125
Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×