Advertisements
Advertisements
प्रश्न
Find the area of the triangle formed by the points
(1, – 1), (– 4, 6) and (– 3, – 5)
Advertisements
उत्तर
Let the vertices A(1, – 1), B(– 4, 6) and C(– 3, – 5)
Area of ∆ABC = `1/2 [(x_1y_2 + x_2y_3 + x_3y_1) - (x_2y_1 + x_3y_2 + x_1y_3)]`
= `1/2[((-4 xx - 5) + (-3 xx - 1) + (1 xx 6)),(-(-3 xx 6) + (1 xx -5) + (- 4 xx - 1))]`
= `1/2[(6 + 20 + 3) - (4 - 18 - 5)]`
= `1/2[29 - (- 19)]`
= `1/2[29 + 19]`
= `1/2 xx 48`
= 24 sq. units
Area of ∆ABC = 24 sq. units
APPEARS IN
संबंधित प्रश्न
A traffic signal board, indicating ‘SCHOOL AHEAD’, is an equilateral triangle with side ‘a’. Find the area of the signal board, using Heron’s formula. If its perimeter is 180 cm, what will be the area of the signal board?
Find the area of a triangle two sides of which are 18 cm and 10 cm and the perimeter is 42 cm.
Find the area of a triangle whose sides are 3 cm, 4 cm and 5 cm respectively.
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)`
Using Heron’s formula, find the area of a triangle whose sides are 10 cm, 24 cm, 26 cm
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 ______.
How much paper of each shade is needed to make a kite given in the following figure, in which ABCD is a square with diagonal 44 cm.
A field is in the shape of a trapezium having parallel sides 90 m and 30 m. These sides meet the third side at right angles. The length of the fourth side is 100 m. If it costs Rs 4 to plough 1 m2 of the field, find the total cost of ploughing the field.
