91Ó°ÊÓ

From given figure, we can say that,

Length of rectangle $=l=x$ft.

Breadth of rectangle $=b=8$ft.

Base of triangle =base $=x$.

Height of triangle $=h=6$ft.

We know that,

Area of triangle $=\frac{1}{2}×base×h$

On substituting values, we get

$⇒$ Area of triangle $=\frac{1}{2}×x×6$

$⇒$ Area of triangle $=3x$.

We know that,

Area of rectangle $=l×b$

On substituting values, we get

$⇒$ Area of rectangle $=x×8$

$⇒$ Area of rectangle $=8x$.

Total area of given figure =Area of triangle +Area of rectangle

On substituting values, we get

$⇒$ Total area of given figure $=$$3x+8x$

$⇒$ Total area of given figure $=$$11x$

Total area of the figure in terms of x is $11xsquarefeet$.

From above part, we got that,

Total area $=11x.$

On substituting values, we get

$154=11x$.

Dividing with $11$on both sides We get

$x=14.$

Therefore, the value of $x=14$feet.