This is an important and exam oriented question from Chapter name- circles
Topic – Angle properties of circles
Chapter number- 15
In this question we have been given that ∠DBC = 58° and BD is a diameter of the circled
And we hve to , calculate:
(i) ∠BDC (ii) ∠BEC (iii) ∠BAC
ICSE Avichal publication
Understanding ICSE Mathematics
Question no 3(a)
Solution:
(a) ∠DBC = 58°
BD is diameter
∠DCB = 90° (Angle in semi-circle)
(i) In ∆BDC
∠BDC + ∠DCB + ∠CBD = 180°
∠BDC = 180°- 90° – 58° = 32°
(ii) BEC = 180o – 32o = 148o
(opposite angles of cyclic quadrilateral)
(iii) ∠BAC = ∠BDC = 32o
(Angles in same segment