This is the basic and conceptual question from Chapter name- circles
Topic – Angle properties of circles
Chapter number- 15
In this ques we have been given the figure of circle and we have to find the value of x
ICSE Avichal publication
Understanding ICSE Mathematics
Question 1
Given ∠CPB = 120o , ∠ACP = 70o
To find, xo i,e., ∠PBD
Reflex ∠CPB = ∠BPO + ∠CPA
1200 = ∠BPD + ∠BPD
(BPD = CPA are vertically opposite ∠s)
2∠BPD = 120o ∠PBD = 1200/2 = 60o
Also ∠ACP and PBD are in the same segment
∠PBD + ∠ACP = 700
Now, In ∆PBD
∠PBD + ∠PDB + ∠BPD = 180o
(sum of all ∠s in a triangle)
700 + xo + 600 = 180o
x = 180o – 130o
x = 50o