Advertisements
Advertisements
प्रश्न
The length of the sides of a triangle are in the ratio 3: 4: 5. Find the area of the triangle if its perimeter is 144 cm.
Advertisements
उत्तर
Let the sides of the triangle are
a = 3x
b = 4x
c = 5x
Given that the perimeter is 144 cm.
Hence
3x + 4x + 5x = 144
⇒ 12x = 144
⇒ x = `144/12`
⇒ x = 12
s = `(a + b + c)/(2)`
= `(12x)/(2)`
= 6x
= 6 × 12
= 72
The sides are a = 36 cm, b = 48 cm and c = 60 cm.
Area of the triangle is
A = `sqrt (s(s - a )( s - b ) (s - c ))`
= `sqrt (72(72 - 36 )( 72 - 48 ) (72 - 60))`
= `sqrt (72 xx 36 xx 24 xx 12)`
= `sqrt746496`
= 864 cm2
APPEARS IN
संबंधित प्रश्न
Two sides of a triangle are 6.4 m and 4.8 m. If the height of the triangle corresponding to 4.8 m side is 6 m;
find :
(i) area of the triangle ;
(ii) height of the triangle corresponding to 6.4 m sides.
The base and the height of a triangle are in the ratio 4: 5. If the area of the triangle is 40 m2; find its base and height.
A field is in the shape of a quadrilateral ABCD in which side AB = 18 m, side AD = 24 m, side BC = 40m, DC = 50 m and angle A = 90°. Find the area of the field.
The lengths of the sides of a triangle are in the ratio 4: 5 : 3 and its perimeter is 96 cm. Find its area.
Use the information given in the adjoining figure to find :
(i) the length of AC.
(ii) the area of an ∆ABC
(iii) the length of BD, correct to one decimal place.
Find the area of a right angled triangle whose hypotenuse is 15cm and the base is 9cm.
The table given below contains some measures of the triangle. Find the unknown values.
| Side 1 | Side 2 | Side 3 | Perimeter |
| 6 cm | 5 cm | 2 cm | ? |
Find the perimeter and the area of a right angled triangle whose sides are 6 feet, 8 feet and 10 feet
In the following figure, all triangles are equilateral and AB = 8 units. Other triangles have been formed by taking the mid points of the sides. What is the perimeter of the figure?
In the following figures, perimeter of ΔABC = perimeter of ΔPQR. Find the area of ΔABC.
