ML Aggarwal Solution Class 10 Chapter 15 Circles Exercise 15.1
Exercise 15.1 Question 1 Using the given information, find the value of x in each of the following figures : Sol : (i) ∠ADB and ∠ACB are in the same segment. ∠ADB = ∠ACB = 50° Now in ∆ADB, ∠DAB + X + ∠ADB = 180° (Angles of a triangles) ⇒42∘+x+50∘=180∘ ⇒x+92∘=180∘ ⇒x=180∘−92∘=88∘ (ii) ∠ABD=∠ACD (Angles in the same segment) But ∠ACD=32° ∴∠ABD=32° Now in ΔABD ∠ABD+∠ADB+∠DAB=180° ⇒32°+45°+x=180° ⇒77°+x=180° ⇒x=180°-77°=103° (iii) ∠BAD=∠BCD (Angles in the same segement) But ∠BAD=20° ∴∠BCD=20∘ ∵∠CEA=90∘ ∴∠CED=90∘ Now in Δ CED, ∠CED+∠BCD+∠CDE=180∘ ⇒90∘+20∘+x=180∘ ⇒110∘+x=180∘ ⇒x=180∘−110∘=70∘ (iv) In ΔABC ∠ABC+∠ACB+∠BAC=180° (∵Sum of angles of a triangle) $\Rightarrow 69...