In a right angled triangle, the hypotenus is (3x + 2) cm long. If the other two sides are (x + 3) cm and 3x cm how do you find x?
1 Answer
Jun 1, 2018
Explanation:
"since they are right angled triangles we can use"since they are right angled triangles we can use
color(blue)"Pythagoras' theorem"Pythagoras' theorem
"the square on the hyotenuse "="sum of squares on the"the square on the hyotenuse =sum of squares on the
color(white)(xxxxxxxxxxxxxxxxxxxxxx)"other 2 sides"×××××××××××other 2 sides
(3x+2)^2=(x+3)^2+(3x)^2(3x+2)2=(x+3)2+(3x)2
cancel(9x^2)+12x+4=x^2+6x+9cancel(+9x^2)
"subtract "12x+4" from both sides"
0=x^2-6x+5
0=(x-1)(x-5)
x-1=0rArrx=1
x-5=0rArrx=5
"substitute these values into the given sides"
"to obtain "3,4,5 " or "8,15,17
"both well known "color(blue)"Pythagorean triples"