original side = s
(s+7)^2 = 256
s+7 = 16
s = 9
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use your good old Pythagorean Theorem:
28^2 + h^2 = 35^2
Note that 28=4*7 and 35=5*7, so what we have here is a 3-4-5 triangle scaled up by 7.
h = 3*7 = 21
(check: 28^2 + 21^2 = 784+441 = 1225 = 35^2)
1. If the sides of a square are lengthened by 7cm, the area becomes 256cm^2. Find the length of a side of the original square.
2. What does it mean to refer to a 20in TV set or a 25in TV set? Such units refer to the diagonal of the screen. A 35 in TV set also has a width of 28inches What is its height.
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