Let the base, height and area of the first triangle be b1 , h1 , and A1 respectively. Let the base, height and area of the second triangle be b2 , h2 and A2 respectively.
A1/A2 = (b1 x h1)/(b2 x h2) ...[Ratio of areas of two tringles is equal to the product of their bases and corresponding ]
A1/A2 = (9 x 5)/(10 x 6)
= 45/60
A1/A2 = 3/4
∴ The ratio of areas of the tringles is 3:4.