Question

3. A triangle has an area of 90 cm?. Find the length of the base if the base is
3 cm more than height​

Answer 1

Answer:

The answer is 15 cm

The procedure is

Step-by-step explanation:

Let the height of triangle be x

They said that base is 3cm more than height so the base will be x + 3

area of triangle = 1/2 ×b×h

90 = 1/2 × ( x +3 ) × x

= 1/2 × x² + 3x

180= x² + 3x

x²+3x-180 = 0

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

x +15 and x -12 are factors [ by factorisation]

x+15=0 x -12 =0

x = -15 x = 12

The height cannot be negative so the height is 12 cm

Base = x + 3 cm

= 12 + 3 cm

15cm

So we can say that the base of the triangle when area is 90cm2 the base will be 15cm