Exams › JEE Main › Maths
In triangle ABC, medians AD and CE have lengths 18 and 27 respectively, and AB = 24. The line CE is extended to meet the circumcircle of triangle ABC at point F. G is the centroid of the triangle. Which of the following statements are correct?
- b = 3 * sqrt(70)
- a = 6 * sqrt(31)
- Area of triangle AGE = (27/4) * sqrt(55)
- EF = 16/3
Correct answer: b = 3 * sqrt(70)
Solution
Median from A (to midpoint D of BC): mₐ² = (2b² + 2c² - a²)/4 = 324, so 2b² + 2*576 - a² = 1296 => 2b² - a² = 144...(1). Median from C (to midpoint E of AB): m_c² = (2a² + 2b² - c²)/4 = 729, so 2a² + 2b² - 576 = 2916 => 2a² + 2b² = 3492 => a² + b² = 1746...(2). From (1): 2b² - a² = 144 => a² = 2b² - 144. Substituting into (2): 2b² - 144 + b² = 1746 => 3b² = 1890 => b² = 630 => b = sqrt(630) = 3*sqrt(70). Then a² = 1746 - 630 = 1116, a = sqrt(1116) = 6*sqrt(31). Both A and B are correct. For option D: G divides CE in 2:1, so CG = 18, GE = 9. By power of a point or intersecting chords: GE * GF = GA * GD. GA = (2/3)*18 = 12, GD = 6. GE*GF = 12*6 = 72. GF = 72/9 = 8. EF = GE + GF = 9 + 8 = 17, not 16/3. So D is wrong.
Related JEE Main Maths questions
- In triangle ABC, if b² + c² = 1999 * a², find the value of (cot B + cot C) / cot A.
- Let A be the set {(n, 2n): n ∈ N} and let B be the set {(2n, 3n): n ∈ N}. What is the intersection A ∩ B?
- Let set A contain 3 elements and set B contain 6 elements. Then the cardinality of their union must satisfy
- Given the sets A = {1, 2, 5} and B = {3, 4, 5, 9}, what is A ∩ B?
- At a conference with 100 attendees, 29 are Indian women and 23 are Indian men. Among the Indian attendees, 4 are doctors, and 24 are either men or doctors. If there are no foreign doctors, how many foreigners and how many women doctors are present at the conference?
- Let X and Y be two non-empty sets, and let A be a non-empty set such that X ∩ A = Y ∩ A = A and X ∪ A = Y ∪ A. Which of the following must be true?
⚔️ Practice JEE Main Maths free + battle 1v1 →