NCERT Exemplar Solutions
Class 10 - Mathematics - CHAPTER 6: Triangles - Exercise 6.1
Question 1

Question.  1

1. In Fig. 6.2, \(\angle BAC = 90^\circ\) and \(AD \perp BC\). Then,

Right triangle with altitude AD to hypotenuse BC

(A)

\(BD\cdot CD = BC^2\)

(B)

\(AB\cdot AC = BC^2\)

(C)

\(BD\cdot CD = AD^2\)

(D)

\(AB\cdot AC = AD^2\)

Detailed Answer with Explanation:

Step 1: The triangle \(ABC\) is a right triangle with \(\angle A = 90^\circ\). So, side \(BC\) is the hypotenuse.

Step 2: The line \(AD\) is drawn from the right angle \(A\) perpendicular to the hypotenuse \(BC\). This line is called the altitude on the hypotenuse.

Step 3: There is a special property of right triangles:
When an altitude is drawn from the right angle to the hypotenuse, the square of the altitude = product of the two parts of the hypotenuse.
In symbols: \(AD^2 = BD \times DC\).

Step 4: From the options, this matches option (C): \(BD \cdot CD = AD^2\).

Final Answer: Option (C).

NCERT Exemplar Solutions Class 10 – Mathematics – CHAPTER 6: Triangles – Exercise 6.1 | Detailed Answers