If triangle ABC is right angled at C, then the value of sec (A + B) is
(a) 0 (b) 1 (c) 2/√3 (d) not defined

CBSE Class 10 Sample Paper for 2020 Boards - Maths Standard
CBSE Class 10 Sample Paper for 2020 Boards - Maths Standard
Last updated at Dec. 16, 2024 by Teachoo
Question 5 If triangle ABC is right angled at C, then the value of sec (A + B) is (a) 0 (b) 1 (c) 2/√3 (d) not defined In Δ ABC Sum of angles = 180° ∠ A + ∠ B + ∠ C = 180° Given Δ ABC is right angled at C, So, ∠ C = 90° Therefore, our equation becomes ∠ A + ∠ B + 90° = 180° ∠ A + ∠ B = 180° – 90° ∠ A + ∠ B = 90° Now, sec (A + B) = sec 90° = 1/cos〖90°〗 = 1/0 = Not defined ∴ Correct answer is option (d)