Published by:
CGP EDU Academic Team
Published on: August 12, 2026
In a triangle ABC, cos A cos B + sin A sin B sin C = 1, then the triangle is -
Text Solution
Verified by ExpertsThe correct answer is:
B
sin C = 
≤ 1
⇒ 1 – cos A cos B – sin A sin B ≤ 0
⇒ 1 – cos (A – B) ≤ 0
⇒ cos (A – B) ≥ 1
⇒ cos (A – B) = 1 –1 ≤ cos θ ≤ 1
⇒ A – B = 0
⇒ A = B
∴ sin C = 
⇒ C = π /2
∴ A = B = π /4
Right Angle Isosceles triangle
Prepare Smarter with CGP Edu
Get practice questions, solutions, and test series in one place.
Write a Review
Share your experience with this question and solution.
Commentary
Send your comment, doubt, correction, or feedback to admin.
Similar Questions
Explore conceptually related problems
In a Δ ABC, if P,Q,R divide sides AB, BC, CA respectively in k : 1. If , then k equals
In a triangle ABC, =
If P is a point on the altitude AD of the triangle ABC such that ∠ PBD = , then AP is equal to -
In a Δ ABC, if a, b, c and A are given, then there are two Δ ’s with third sides c 1 and c 2 , then…
In a triangle ABC, tan = , tan = , then –
If in a triangle ABC sines of angles A and B satisfy the
equation 4 x 2 – 2 x + 1 = 0, then cos (A…