KVPY2012MathematicsProperties of Triangles
In a triangle ABC , it is known that AB = AC . Suppose D is the mid- point of AC and BD = BC =2 . Then the area of the triangle ABC is -
Options
- A2
- B2 2
- C7
- D27
Correct answer
C. 7
Step-by-step solution
We know array l AB ²+ BC ²=2 ( CD ²+ BD ² ) AB ²+4=2 ( AB ² 4 +4 ) AB ²+4= AB ² 2 +8 AB ² 2 =4 AB ²=8 AB =2 2 array Now Area = 1 2 2 7 = 7 square unit.