Find the length of the shorter diagonal of a rhombus if:

(a) The length of the longer diagonal is 15 and the area is 90.

(b) The lengths of the diagonals are in the ratio of 2:3 and the area of the rhombus is 147.

Respuesta :

a) Area of rhombus = ½ * (diagonal1)*(diagonal 2)

Let diagonal (D2 )= longer diagonal = 15 and diagonal (D1) = shorter diagonal

90 = ½ (D1)*15

90 = 7.5 D1

Now divide both side by 7.5

90/7.5 = d1

D1= 12 units.

b) Area of rhombus = ½ * (diagonal1)*(diagonal 2)

Let the ratio be [tex] x [/tex]

Diagonal 1= [tex] 2x [/tex]

Diagonal 2= [tex] 3x [/tex]

147 = ½ * [tex] (2x)*(3x) [/tex]

Multiply both side by 2

294 = [tex] (2x)*(3x) [/tex]

294 = 6[tex] x^2 [/tex]

Divide both side by 6

294/6 = 6[tex] x^2 [/tex]/6

49 = [tex] x^2 [/tex]

[tex] x [/tex]= 7 unit