2 bases of a trapezium are in ratio 2:5 given height is 40 and area 2800 find length of bases?
2007-02-09 20:28:41 · 3 answers · asked by DUDE 1 in Science & Mathematics ➔ Mathematics
Trapezium
There are two common definitions of the trapezium. The American definition is a quadrilateral with no parallel sides. The British definition for a trapezium is a quadrilateral with two sides parallel (Bronshtein and Semendyayev 1977, p. 174). Such a trapezium is equivalent to a trapezoid.
American or British?
2007-02-09 20:38:33 · answer #1 · answered by tom4bucs 7 · 0⤊ 0⤋
Area of trapezium = (1/2)[(a + b) h] where a is length of top, b is length of bottom and h is height.
b = (2/5) a in this example.
(1/2)[a + (2/5) a] (40) = 2800
20 x (7/5) a = 2800
28 a = 2800
a = 100 and b = 40
Length of bases are 100 and 40
2007-02-10 05:17:36 · answer #2 · answered by Como 7 · 0⤊ 0⤋
area = 1/2 * (base1 + base2 ) * height
2800 = 1/2 * (b1 + b2) *40
b1 + b2 =140
b1 / b2 = 2 /5
b1 = .4 b2
1.4b2 = 140
b2 = 100
b1=40
ans = 100 ,40
2007-02-10 04:42:14 · answer #3 · answered by usp 2 · 0⤊ 0⤋