Roger N. answered 07/29/21
. BE in Civil Engineering . Senior Structural/Civil Engineer
Solution:
h = L -14 in, hyp = L + 2in , also hypotenuse = √(L2 + h2) = L + 2in take square of both sides
L2+ h2 = ( L + 2)2 , but h = L-14 substitute h and expand
L2 + (L -14)2 = L2 + 4L + 4, L2 + L2 - 28L + 196 = L2 + 4L + 4, simplify and rearrange
L2 - 32 L + 192= 0 Solve by completing the square
L2-32 L = -192 , b=32 and (b/2) = -16, ( b/2)2 = 256 add to both sides
L2 -32 L + 256 = -192 + 256 = 64
(L-16)2 = 64 take square root of both sides, L -16 = ± 8 , L -16 = 8. L = 24 in, L -16 = -8. L = 8 in
Try L = 24 in, h = 24 -14 = 10in . hyp = √(24)2+(10)2 = √(576 + 100) = 26 in = L + 2 = 24 + 2 = 26 in,
Try L = 8in, h = 8-14 =-6 -ve value and this option is not possible therefore L = 24 in