Herons Formula CBSE Questions & Answers

Herons Formula

This is Mathematics Class 09 Herons Formula CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
The area of a triangle with base 8 cm and height 10 cm is
  • A
    80 \(c{m^2}\)
  • B
    18 \(c{m^2}\)
  • C
    40 \(c{m^2}\)
    Correct
  • D
    20 \(c{m^2}\)
2
The base of a right triangle is 8 cm and hypotenuse is 10 cm. Its area will be
  • A
    80 \(c{m^2}\)
  • B
    40 \(c{m^2}\)
  • C
    24 \(c{m^2}\)
    Correct
  • D
    48 \(c{m^2}\)
3
A triangle ABC in which AB = AC = 4 cm and \(\angle A = {90^o}\), has an area of
  • A
    12 \(c{m^2}\)
  • B
    4 \(c{m^2}\)
  • C
    8 \(c{m^2}\)
    Correct
  • D
    16 \(c{m^2}\)
4
If the side of an equilateral triangle is 4 cm, then its area is
  • A
    \(4\sqrt 3 \;c{m^2}\)
    Correct
  • B
    \(12\sqrt 3 \;c{m^2}\)
  • C
    \(8\sqrt 3 \;c{m^2}\)
  • D
    \(16\sqrt 3 \;c{m^2}\)
5
If the perimeter of an equilateral triangle is 24 m, then its area is
  • A
    \(8\sqrt 3 \;{m^2}\)
  • B
    \(20\sqrt 3 \;{m^2}\)
  • C
    \(24\sqrt 3 \;{m^2}\)
  • D
    \(16\sqrt 3 \;{m^2}\)
    Correct
6
The length of each side of an equilateral triangle having an area of \(25\sqrt 3 \;c{m^2}\) is
  • A
    10 cm
    Correct
  • B
    25 cm
  • C
    5 cm
  • D
    15 cm
7
If the area of an equilateral triangle is \(36\sqrt 3 \;c{m^2}\) , then the perimeter of the triangle is
  • A
    \(12\sqrt 3 \;cm\)
  • B
    36 cm
    Correct
  • C
    12 cm
  • D
    18 cm
8
The edges of a triangular board are 6 cm, 8 cm and 10 cm. The cost of painting it at the rate of 70 paise per \(c{m^2}\) is
  • A
    Rs 16
  • B
    Rs 17
  • C
    Rs 7
  • D
    Rs 16.80
    Correct
9
The perimeter of a rhombus is 20 cm. If one of its diagonals is 6 cm, then its area is
  • A
    36 \(c{m^2}\)
  • B
    24 \(c{m^2}\)
    Correct
  • C
    28 \(c{m^2}\)
  • D
    20 \(c{m^2}\)
10
The area of a rhombus of 96\(c{m^2}\). If one of its diagonals is 16 cm, then the length of its side is
  • A
    6 cm
  • B
    12 cm
  • C
    10 cm
    Correct
  • D
    8 cm
11
An isosceles right triangle has area 8\(c{m^2}\). The length of the hypotenuse is
  • A
    \(\sqrt {32} \;cm\)
    Correct
  • B
    6 cm
  • C
    4 cm
  • D
    8 cm
12
The area of an isosceles triangle having base 24 cm and length of one of the equal sides 20 cm is
  • A
    240 \(c{m^2}\)
  • B
    196 \(c{m^2}\)
  • C
    192 \(c{m^2}\)
    Correct
  • D
    480 \(c{m^2}\)
13
The perimeter of an isosceles triangle is 32 cm. the ratio of the equal side to its base is 3 : 2. Then area of the triangle is
  • A
    \(32\sqrt 2 \;c{m^2}\)
    Correct
  • B
    16 \(c{m^2}\)
  • C
    \(16\sqrt 2 \;c{m^2}\)
  • D
    32 \(c{m^2}\)
14
If the perimeter and base of an isosceles triangle are 11 cm and 5 cm respectively, then its area is
  • A
    \({5 \over 2}\sqrt {11} \;c{m^2}\)
  • B
    \({5 \over 8}\sqrt {11} \;c{m^2}\)
  • C
    \({5 \over 4}\sqrt {11} \) \(c{m^2}\)
    Correct
  • D
    \(5\sqrt {11} \) \(c{m^2}\)
15
The area of a regular hexagon of side 4 cm is
  • A
    \(24\sqrt 3 \;c{m^2}\)
    Correct
  • B
    \(6\sqrt 3 \;c{m^2}\)
  • C
    \(16\sqrt 3 \;c{m^2}\)
  • D
    \(4\sqrt 3 \;c{m^2}\)