Question

a triangle has an area of 90 cm square find the length of the base if the base is 3 cm more than height​

Answer 1

Answer:

15cm

Step-by-step explanation:

given,

area of triangle =90cm²

and

let

height is x

length of base is x+3

we know, area of triangle =(height*base)/2

=> 90=x.(x+3)/2

=> 180= x²+3x

=> x²+3x -180= 0

=> x²+15x-12x-180=0

=> x(x+15)-12(x+15)=0

=> (x-12)(x+15)=0

=> x=12 and x=-15

length can never be negative so,

height =x= 12

and

length of base is x+3=12+3

=15cm

Answer 2

Answer:

15cm

Step-by-step explanation:

given,

area of triangle =90cm²

and

let

height is x

length of base is x+3

we know, area of triangle =(height*base)/2

=> 90=x.(x+3)/2

=> 180= x²+3x

=> x²+3x -180= 0

=> x²+15x-12x-180=0

=> x(x+15)-12(x+15)=0

=> (x-12)(x+15)=0

=> x=12 and x=-15

length can never be negative so,

height =x= 12

and

length of base is x+3=12+3

=15cm