1. In an isosceles triangle ABC, given that AB = AC = 25 cm and BC = 14 cm, we need to find the measure of the altitude from A to BC. Let the altitude from A meet BC at point D. Since the triangle is isosceles, the altitude AD also acts as the median, dividing BC into two equal parts: BD = DC = BC / 2Read more

    In an isosceles triangle ABC, given that AB = AC = 25 cm and BC = 14 cm, we need to find the measure of the altitude from A to BC.

    Let the altitude from A meet BC at point D. Since the triangle is isosceles, the altitude AD also acts as the median, dividing BC into two equal parts:
    BD = DC = BC / 2 = 14 / 2 = 7 cm.

    Now, consider ΔABD, which is a right triangle because AD is perpendicular to BC. Using the Pythagorean theorem:
    AB² = AD² + BD²
    25² = AD² + 7²
    625 = AD² + 49
    AD² = 625 – 49
    AD² = 576
    AD = √576 = 24 cm.

    Thus, the measure of the altitude from A on BC is 24 cm.

    Click here for more:
    https://www.tiwariacademy.in/ncert-solutions-class-10-maths-chapter-6/

    See less
    • 18
  2. When AD is the altitude from vertex A to side BC, it divides ΔABC into two right triangles, ΔABD and ΔACD. Using the property of the area of a triangle, we know that the area can be expressed in two ways: 1. Area = (1/2) × base × height = (1/2) × BC × AD. 2. Area = (1/2) × AB × AC × sin(∠BAC). EquatRead more

    When AD is the altitude from vertex A to side BC, it divides ΔABC into two right triangles, ΔABD and ΔACD. Using the property of the area of a triangle, we know that the area can be expressed in two ways:
    1. Area = (1/2) × base × height = (1/2) × BC × AD.
    2. Area = (1/2) × AB × AC × sin(∠BAC).

    Equating the two expressions for the area:
    (1/2) × BC × AD = (1/2) × AB × AC × sin(∠BAC).

    Since sin(∠BAC) = AD / AB (from the definition of sine in ΔABD), substituting this value simplifies the equation to:
    BC × AD = AB × AC.

    Thus, the correct answer is AB × AC = BC × AD.

    Click here for more:
    https://www.tiwariacademy.in/ncert-solutions-class-10-maths-chapter-6/

    See less
    • 12
  3. In ΔABC, given that ∠B = 90°, AB = 6 cm, and BC = 8 cm, we can determine sin A using the definition of sine in a right triangle. First, calculate the hypotenuse AC using the Pythagorean theorem: AC² = AB² + BC² AC² = 6² + 8² AC² = 36 + 64 AC² = 100 AC = √100 = 10 cm Now, recall that sin A is definedRead more

    In ΔABC, given that ∠B = 90°, AB = 6 cm, and BC = 8 cm, we can determine sin A using the definition of sine in a right triangle.

    First, calculate the hypotenuse AC using the Pythagorean theorem:
    AC² = AB² + BC²
    AC² = 6² + 8²
    AC² = 36 + 64
    AC² = 100
    AC = √100 = 10 cm

    Now, recall that sin A is defined as the ratio of the length of the side opposite to ∠A (BC) to the hypotenuse (AC):
    sin A = (opposite side) / (hypotenuse)
    sin A = BC / AC
    sin A = 8 / 10

    Thus, the correct answer is 8/10.

    Click here for more:
    https://www.tiwariacademy.in/ncert-solutions-class-10-maths-chapter-6/

    See less
    • 16
  4. Similarity of triangles is based on the principle that when two triangles have the same shape but not necessarily the same size, they are considered similar. This occurs if and only if their corresponding angles are equal. When the angles are equal, the ratios of the lengths of their corresponding sRead more

    Similarity of triangles is based on the principle that when two triangles have the same shape but not necessarily the same size, they are considered similar. This occurs if and only if their corresponding angles are equal. When the angles are equal, the ratios of the lengths of their corresponding sides are also equal (this is known as the Angle-Angle or AA criterion for similarity).

    The other options are incorrect because:
    – “Their corresponding sides are equal” describes congruence, not similarity.
    – “Their perimeters are equal” does not guarantee similarity, as triangles with the same perimeter can have different shapes.
    – “Their areas are equal” also does not ensure similarity, as triangles with the same area can have different shapes and dimensions.

    Thus, the correct answer is “Their corresponding angles are equal.”

    Click here for more:
    https://www.tiwariacademy.in/ncert-solutions-class-10-maths-chapter-6/

    See less
    • 11