Answer:7 x 10
1) Can be done by trail and error
Or
2) setting and slowing two equations
Step-by-step explanation:
If a and b are sides of rectangle
(1). 2a + 2b = 34
(2). ab = 70
From 1
a= 17-b
Substitute above a to (2)
(17-b)b = 70
17b - b^2 = 70
-b^2 + 17b -70 = 0
Multiple above by -1
b^2 - 17b + 70 = 0
Solving quadratic equation by factorising
(b-7)(b-10)=0
b=7 or b=10
If b= 7. a =10
If b=10. a=7