Answer: Part a: x=sqrt(104) in; Part b: x=sqrt(5) in
Step-by-step explanation:
Part a:
Because the figure has a right angle (signified by the square), it is a right triangle. Therefore, the Pythagorean Theorem, a²+b²=c² where c is the hypotenuse (longest side) and a and b are the legs (shorter sides), applies. Thus:
a²+b²=c²
The 15 in side is opposite the right angle, so it is the hypotenuse.
The 11 in side and x in side are not opposite the right angle, so they are legs.
11²+x²=15²
121+x²=225
(121+x²)-121=225-121
x²=104
sqrt(x²)=sqrt(104)
x=±sqrt(104)
Reject x=-sqrt(104) because a negative side length in a triangle is impossible. Therefore,
x=sqrt(104) in
Part b:
The figure is a right triangle. Therefore, the Pythagorean Theorem (a²+b²=c²) applies. Hence,
5²+(2x)²=(3x)²
25+4x²=9x²
(25+4x²)-4x²=9x²-4x²
25=5x²
5=x²
sqrt(5)=sqrt(x²)
x=±sqrt(5)
Reject x=-sqrt(5) because a negative side length is impossible.
The answer must be x=sqrt(5) in.
