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 cost of turfing a triangular field at the rate of Rs. 45 per 100 \({m^2}\) is Rs. 900. If the double the base of the triangle is 5 times its height, then its height is
  • A
    44 cm
  • B
    40 cm
    Correct
  • C
    42 cm
  • D
    32 cm
2
The sides of a triangle are 56 cm, 60 cm and 52 cm long. Then the area of the triangle is
  • A
    1322 \(\;c{m^2}\)
  • B
    1311 \(\;c{m^2}\)
    Correct
  • C
    1392 \(\;c{m^2}\)
  • D
    1344 \(\;c{m^2}\)
3
The area of an isosceles triangle having base 2 cm and the length of one of the equal sides 4 cm, is
  • A
    \(2\sqrt {15} \;c{m^2}\)
  • B
    \(\sqrt {{{15} \over 2}} \;c{m^2}\)
  • C
    \(\sqrt {15} \;c{m^2}\)
    Correct
  • D
    \(4\sqrt {15} \;c{m^2}\)
4
The edges of a triangular board are 6 cm, 8 cm and 10 cm. The cost of painting it at the rate of 9 paise per \(\;c{m^2}\) is
  • A
    Rs. 2.16
    Correct
  • B
    Rs. 2.00
  • C
    Rs. 2.48
  • D
    Rs. 3.00
5
The area of equilateral triangle of side ‘a’ is \(4\sqrt 3 \;c{m^2}\). Its height is given by
  • A
    \(2\sqrt 3 \;cm\)
    Correct
  • B
    \(\sqrt 3 \)cm
  • C
    \({2 \over {\sqrt 3 }}cm\)
  • D
    \({1 \over 3}cm\)
6
If side of a scalene \(\triangle \) is doubled then area would be increased by
  • A
    none
  • B
    50 \(\% \)
  • C
    100 \(\% \)
    Correct
  • D
    25 \(\% \)
7
In each side of a \(\triangle \) is halved then its perimeter will be decreased by
  • A
    25 \(\% \)
  • B
    none
  • C
    100 \(\% \)
    Correct
  • D
    50 \(\% \)
8
Length of perpendicular drawn on smallest side of scalene triangle is
  • A
    none
  • B
    No relation
  • C
    largest
    Correct
  • D
    smallest
9
Length of perpendicular drawn on longest side of a scale \(\triangle \) is
  • A
    smallest
    Correct
  • B
    No relation
  • C
    none
  • D
    largest
10
Semiperimeter of scalene triangle of side k, 2k and 3k is
  • A
    3k
    Correct
  • B
    4k
  • C
    k
  • D
    2k
11
The sides of a triangle are 5 cm, 12 cm and 13 cm. then its area is
  • A
    0.0015 \({m^2}\)
  • B
    0.0024 \({m^2}\)
  • C
    0.0026 \({m^2}\)
  • D
    0.003 \({m^2}\)
    Correct
12
If the sides of a triangle are doubled, then its area
  • A
    remains the same
  • B
    becomes three times
  • C
    becomes doubled
  • D
    becomes four times
    Correct
13
The area of a right angled triangle is 20 \({m^2}\) and one of the sides containing the right triangle is 4 cm. Then the altitude on the hypotenuse is
  • A
    8 cm
  • B
    \({{10} \over {\sqrt {41} }}cm\)
  • C
    \({{20} \over {\sqrt {29} }}cm\)
    Correct
  • D
    10 cm
14
Area of an equilateral triangle of side 10 cm is :
  • A
    \(50\sqrt 3 \;c{m^2}\)
  • B
    \(100\sqrt 3 \;c{m^2}\)
  • C
    \(10\sqrt 3 \;c{m^2}\)
  • D
    \(25\sqrt 3 \;c{m^2}\)
    Correct
15
The length of the sides of a triangle are 5x, 5x and 8x. The area of the triangle is :
  • A
    144 \({x^2}\) sq. units
  • B
    12 \({x^2}\) sq. units
    Correct
  • C
    24 \({x^2}\) sq. units
  • D
    100 \({x^2}\) sq. units