The attitude of a right triangle is 7 cm less than its bass. If the hypotenuse is 13cm, find the other two sides [x=12]
Answers
Answer :-
Given :- Hypotenuse = 13 cm ;
Altitude is 7 less than base.
To Find :- Base & altitude.
Solution :-
Let the base be x ;
Altitude = x - 17.
By Pythagoras Theorem :-
(Hyp.)² = (A)² + (b)²
-> (13)² = (x - 7)² + (x)²
-> 169 = (x² + 49 - 14x) + x²
-> 169 = 2x² + 49 - 14x
-> 169 - 49 - 2x² + 14x = 0
-> 120 - 2x² + 14x = 0
-> -2x² + 14x + 120
Now, Factorise it ;
-> -2x² + 24x - 10x + 120
-> -2x (x - 12) - 10 (x - 12)
-> (-2x - 10) (x - 12)
-> x - 12 = 0
-> x = 12
So, the base is 12 cm ;
So, the base is 12 cm ;Altitude = 12 - 7 = 5 cm.
☞ The attitude of a right triangle is 7 cm less than its base.
» Let the base (B) of triangle be x cm
• Altitude is 7cm less than its base.
» Altitude = (x - 7) cm
» Hypotenuse = 13 cm
_____________________________
We know that
H² = B² + P²
________ [By Pythagoras theorem]
=> (13)² = (x)² + (x - 7)²
=> 169 = x² + x² + 49 - 14x
=> 169 - 49 = 2x² - 14x
=> 120 = 2x² - 14x
=> 2x² - 14x - 120 = 0
• Take 2 common
=> 2(x² - 7x - 60) = 0
=> x² - 7x - 60 = 0
=> x² - 12x + 5x - 60 = 0
=> x(x - 12) +5(x - 12) = 0
=> (x + 5) (x - 12) = 0
• x + 5 = 0
=> x = - 5 (side can't be in negative. So, rejected.)
• x - 12 = 0
=> x = 12
_______________________________
• Base of triangle = x = 12 cm
• Altitude of triangle = x - 7 = 12 - 7 = 5 cm
_______________________________
The other two side are 12 cm and 5 cm.
___________ [ANSWER]