InΔABC,if ∠A+∠B=108∘ and ∠B+∠C=130∘,find∠A,∠B and∠C.
Let ∠A+∠B=108∘ and ∠B+∠C=130∘.⇒∠A+∠B+∠B+∠C=108∘+130∘⇒∠A+∠B+∠C+∠B=238∘∵∠A+∠B+∠C=180∘⇒180∘+∠B=238∘⇒∠B=58∘∴∠C=130∘−∠B=130∘−58∘=72∘∴∠A=108∘−∠B=108∘−58∘=50∘
In ΔABC, if ∠A+∠B=125∘ and ∠A+∠C=113∘, find ∠A,∠B and ∠C.
InΔABC,if∠B=76∘ and ∠C=48∘,find ∠A.
In ΔABC, AB = AC and ∠B=50∘. Then ∠A=?(a) 40∘ (b) 50∘ (c) 80∘ (d) 130∘