Question

the parallel sides of a trapezium are in the ratio 3 : 4 and the perpendicular distance between them is 12 cm. if the area of the trapezium is 630 cmsquare, then its shorter of the parallel sides is??

Answer 1

parallel sides of trapezium =  3 : 4 
height =  12 cm
area =  630 cm^2
let parallel sides of trapezium =  3x and 4x

area of trapezium = $\frac{1}{2} (sum of parallel sides ) height$
    630 cm^2 = $\frac{1}{2} * 7x * 12$
     x  =  630 / 42 
          =  15 
  parallel sides are =  4 * 15 =  60 cm
                                3 * 15  = 45 cm 
     
    

Answer 2

so formula for area of trapezium(A) =   x sum of parallel sides(S) x perpendicular distance between parallel sides (P)

so here S = 4x + 3x cm = 7x cm

A = 630 cm²

P =  12 cm

so 630 =   x 7x x 12

⇒  x =  $\frac{630*2}{7*12}$

⇒  3x = 45 cm ANSWER