The answer is 75
Bc 45+30=75
Uhm..
From what I can understand the height:width ratio is 3:4 so if the width is ten then you will be increasing the ratio by 2.5. So all you have to do is multiply 3 by 2.5.
The height is 7.5cm
Width = w
Length = 5w
Given,
Perimeter = 276 ft
5w * w = 276
w² = 55.2
--- w = 7.429670248402684 ≈ 7.43 ft
--- l = 5w = 5*7.43 = <span>37.14835124201342 </span>≈ 37.15 ft
Check the picture below.
notice, the width is the cosine and the length is the sine.