Answer:
x = 4.5.
Step-by-step explanation:
it is given that the perimeter of a triangle is 21.7 cm. Its side lengths are 10, 5.2, and x+2.
Perimeter of a triangle = Sum of its all sides.
[tex]10+5.2+(x+2)=21.7[/tex]
Combine like terms.
[tex]17.2+x=21.7[/tex]
Subtract 17.2 from both sides.
[tex]x=21.7-17.2[/tex]
[tex]x=4.5[/tex]
Therefore, the value of x is 4.5.