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State True or False and select the corre...

State True or False and select the correct option .
P. In a `DeltaABC` in which AB=AC, the altitude AD bisects BC .
Q. The sum of any two sides of a triangle is greater than twice the median drawn to the third side .
R . If D is the mid-point of the hypotenuse AC of a right `DeltaABC`, then BD=AC .
S. Perimeter of a triangle is equal to the sum of its three medians .
T. If the altitudes AD, BE and CF of `DeltaABC` are equal, then `DeltaABC` is equilateral .

A

`{:(P,Q,R,S,T),("True","True","False","False","True"):}`

B

`{:(P,Q,R,S,T),("True","False","True","False","True"):}`

C

`{:(P,Q,R,S,T),("False","True","False","True","True"):}`

D

`{:(P,Q,R,S,T),("True","True","False","True","True"):}`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question step by step, we will analyze each statement (P, Q, R, S, T) and determine if they are true or false. ### Step 1: Analyze Statement P **Statement P**: In a triangle ABC in which AB = AC, the altitude AD bisects BC. 1. **Draw Triangle ABC**: Start by drawing triangle ABC with AB = AC, making it an isosceles triangle. 2. **Draw Altitude AD**: Draw the altitude from A to BC, which meets BC at point D. 3. **Congruent Triangles**: By the properties of isosceles triangles, triangles ADB and ADC are congruent (using the SAS criterion: AB = AC, AD = AD, and angle ADB = angle ADC). 4. **Conclusion**: Since triangles ADB and ADC are congruent, it follows that BD = DC, which means AD bisects BC. **Result**: True ### Step 2: Analyze Statement Q **Statement Q**: The sum of any two sides of a triangle is greater than twice the median drawn to the third side. 1. **Draw Triangle ABC**: Draw triangle ABC. 2. **Draw Median AD**: Draw the median from A to BC, meeting BC at point D. 3. **Construct Point E**: Extend AD to point E such that D is the midpoint of AE. 4. **Use Triangle Inequality**: According to the triangle inequality, AB + AC > AD + AD, which simplifies to AB + AC > 2AD. 5. **Conclusion**: This statement is true. **Result**: True ### Step 3: Analyze Statement R **Statement R**: If D is the midpoint of the hypotenuse AC of a right triangle ABC, then BD = AC. 1. **Draw Right Triangle ABC**: Draw a right triangle ABC with right angle at B. 2. **Identify Midpoint D**: Mark D as the midpoint of hypotenuse AC. 3. **Use Properties of Right Triangles**: In a right triangle, the median to the hypotenuse is half the length of the hypotenuse. Thus, BD = 1/2 AC. 4. **Conclusion**: This statement is false because BD is not equal to AC. **Result**: False ### Step 4: Analyze Statement S **Statement S**: The perimeter of a triangle is equal to the sum of its three medians. 1. **Understand Perimeter and Medians**: The perimeter of a triangle is the sum of its three sides, while the sum of the medians is not equal to the perimeter. 2. **Conclusion**: This statement is false. **Result**: False ### Step 5: Analyze Statement T **Statement T**: If the altitudes AD, BE, and CF of triangle ABC are equal, then triangle ABC is equilateral. 1. **Draw Triangle ABC**: Draw triangle ABC. 2. **Draw Equal Altitudes**: Draw altitudes AD, BE, and CF such that they are all equal. 3. **Use Properties of Triangles**: If all altitudes are equal, it implies that all sides must also be equal, thus making triangle ABC equilateral. 4. **Conclusion**: This statement is true. **Result**: True ### Final Summary of Results - P: True - Q: True - R: False - S: False - T: True ### Correct Option The correct option is the one that states: P and Q are true, R and S are false, and T is true.
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