Refer to figure, an 11-foot deep ditch is being excavated in Type C soil. The bottom of the ditch is 3 feet wide, sloped regularly, what is the width at the top? (assume its sloped 1:1)

Refer to figure, an 11-foot deep ditch is being excavated in Type C soil. The bottom of the ditch is 3 feet wide, sloped regularly, what is the width at the top? (assume its sloped 1:1)