Advertisements
Advertisements
Question
Find the area of a triangle two sides of which are 18 cm and 10 cm and the perimeter is 42 cm.
Advertisements
Solution
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
RELATED QUESTIONS
The triangular side walls of a flyover have been used for advertisements. The sides of the walls are 122m, 22m, and 120m (see the given figure). The advertisements yield an earning of ₹ 5000 per m2 per year. A company hired one of its walls for 3 months. How much rent did it pay?
A triangle has sides 35 cm, 54 cm and 61 cm long. Find its area. Also, find the smallest of its altitudes ?
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 area of the shaded region in the given figure.
Find the area of a quadrilateral ABCD in which AB = 42 cm, BC = 21 cm, CD = 29 cm, DA =34 cm and diagonal BD =20 cm.
Find the area of an isosceles triangle having the base x cm and one side y cm.
A man walks near a wall, such that the distance between him and the wall is 10 units. Consider the wall to be the Y-axis. The path travelled by the man is
The perimeter of a triangular plot is 600 m. If the sides are in the ratio 5 : 12 : 13, then find the area of the plot
The perimeter of an isosceles triangle is 32 cm. The ratio of the equal side to its base is 3 : 2. Find the area of the triangle.
A rhombus shaped sheet with perimeter 40 cm and one diagonal 12 cm, is painted on both sides at the rate of Rs 5 per m2. Find the cost of painting.
