when keisha installed a fence along the 200 feet perimeter of her rectangular back yard she left and opening for GATE in diagram below she used X to represent the length of the gate

Perimeter of her rectangular back yard is: 200 ft
⇒ 2(30 + 60 + x) = 200
⇒ 30 + 60 + x = 200/2 = 100
⇒ 90 + x = 100
⇒ x = 100 - 90 = 10
ANSWER: A.10
Ok done. Thank to me :>