Question

the base and height of a triangle are in the ratio 7:5.if the area of triangle is 70cm2;find its base and height.

Answer 1

Area of triangle is = 1/2×base×height
Given that base and height are in ratio 7:5
Then let the base be 7x cm and height be 5x cm.
Then area of triangle will be A=1/2× 7x × 5x
Given area us 70 cm so
70=1/2 × 35x^2
140 = 35x^2
Then dividing both sides by 35 we get
4=x^2
Now taking square root on both sides we get
2=x
So we obtain x equal to 2.
Above we have assumed base =7x
So now the base will be 7×2=14
And height was =5x

Answer 2

let the side be x
  given height and base are in the ratio =7:5
                    height=5x
                      base=7x
                   given area =70cm2
                ∴ area =1/2 b*h
                             =1/2*7x*5x=70cm2
                             =1/2*35x2=70cm2
                              =35x2=140cm2
                               =x2=140/35
                                 =x2=4
                                    x=2
                                 ∴base=7*2=14cm
                                     height=5*2=10cm