Advertisements
Advertisements
प्रश्न
ΔABC is right angled at A (see the given figure). AD is perpendicular to BC. If AB = 5 cm, BC = 13 cm and AC = 12 cm, Find the area of ΔABC. Also find the length of AD.
उत्तर
Area = `1/2 xx "Base" xx "Height"`
Area of ΔABC = `1/2 xx "AB" xx "AC"`
= `1/2 xx 5 xx 12`
= 30 cm2
Also, area of triangle = `1/2 xx "AD" xx "BC"`
30 = `1/2 xx "AD" xx 13`
`(30 xx 2)/13` = AD
AD = 4.6 cm
APPEARS IN
संबंधित प्रश्न
Prove that the area of a triangle with vertices (t, t −2), (t + 2, t + 2) and (t + 3, t) is independent of t.
Find equation of line joining (3, 1) and (9, 3) using determinant.
The point A divides the join of P (−5, 1) and Q(3, 5) in the ratio k:1. Find the two values of k for which the area of ΔABC where B is (1, 5) and C(7, −2) is equal to 2 units.
Prove that the points (a, b), (a1, b1) and (a −a1, b −b1) are collinear if ab1 = a1b.
Find the area of a triangle whose sides are 9 cm, 12 cm and 15 cm ?
Find the centroid of ΔABC whose vertices are A(-1, 0) B(5, -2) and C(8,2)
Find the value of k so that the area of the triangle with vertices A (k+1, 1), B(4, -3) and C(7, -k) is 6 square units
Show that the following points are collinear:
(i) A(2,-2), B(-3, 8) and C(-1, 4)
In ☐ABCD, l(AB) = 13 cm, l(DC) = 9 cm, l(AD) = 8 cm, find the area of ☐ABCD.
The points (1,1), (-2, 7) and (3, -3) are ______.
