Advertisements
Advertisements
प्रश्न
Find the area of the triangle formed by the points
(–10, –4), (–8, –1) and (–3, –5)
Advertisements
उत्तर
Let the vertices be A(–10, –4), B(–8, –1) 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[(50 + 3 + 32) - (12 + 40 + 10)]`
= `1/2[((-8 xx -4) + (-10 xx -5) + (-3 xx -1)),(-(-1 xx -10) + (-4 xx -3) + (-5 xx -8))]`
= `1/2[85 - 62]`
= `1/2[23]`
= 11.5
Area of ∆ACB = 11.5 sq.units
APPEARS IN
संबंधित प्रश्न
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?

The lengths of the sides of a triangle are in the ratio 3 : 4 : 5 and its perimeter is 144 cm. Find the area of the triangle and the height corresponding to the longest side.
A rhombus sheet, whose perimeter is 32 m and whose one diagonal is 10 m long, is painted on both sides at the rate of Rs 5 per m2. Find the cost of painting.
Sides of a triangle are cm 45 cm, 39 cm and 42 cm, find its area.
Look at the measures shown in the adjacent figure and find the area of ☐ PQRS.

Determine whether the sets of points are collinear?
`(-1/2, 3), (-5, 6) and (-8, 8)`
The area of triangle formed by the points (− 5, 0), (0, – 5) and (5, 0) is
Using Heron’s formula, find the area of a triangle whose sides are 10 cm, 24 cm, 26 cm
Using Heron’s formula, find the area of a triangle whose sides are 1.8 m, 8 m, 8.2 m
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.
