Advertisements
Advertisements
प्रश्न
Find the area of a triangle two sides of which are 18 cm and 10 cm and the perimeter is 42 cm.
उत्तर
Let the third side of the triangle be x.
The perimeter of the given triangle = 42 cm
18 cm + 10 cm + x = 42
x = 14 cm
s = `"Perimeter"/2`
= `42/2 cm`
= 21 cm
By Heron's formula,
Area of a triangle = `sqrt(s(s-a)(s-b)(s-c))`
Area of the given triangle = `(sqrt(21(21-18)(21-10)(21-14)))cm^2`
= `(sqrt(21(3)(11)(7)))cm^2`
= `21sqrt11 cm^2`
APPEARS IN
संबंधित प्रश्न
The perimeter of an isosceles triangle is 42 cm and its baše is (32) times each of the equal sides. Find the length of each side of the triangle, area of the triangle and the height of the triangle.
Find the areas of the given plot. (All measures are in metres.)
Determine whether the sets of points are collinear?
`(-1/2, 3), (-5, 6) and (-8, 8)`
Determine whether the sets of points are collinear?
(a, b + c), (b, c + a) and (c, a + b)
Find the area of triangle FED
Find the area of a triangle formed by the lines 3x + y – 2 = 0, 5x + 2y – 3 = 0 and 2x – y – 3 = 0
An advertisement board is in the form of an isosceles triangle with perimeter 36 m and each of the equal sides are 13 m. Find the cost of painting it at ₹ 17.50 per square metre.
An isosceles right triangle has area 8 cm2. The length of its hypotenuse is ______.
The perimeter of a triangular field is 420 m and its sides are in the ratio 6 : 7 : 8. Find the area of the triangular field.
The sides of a quadrilateral ABCD are 6 cm, 8 cm, 12 cm and 14 cm (taken in order) respectively, and the angle between the first two sides is a right angle. Find its area.
