Using the trigonometric tangent function equation, calculate the base length $($B$),$ if the height H $=15\mathrm{.}5$ m and the friction angle of a pile of broken rock in a bench blasting exercise is $\backslash$phi $=40\backslash$deg $.$ Identified by its base B and height H$,$ the pile of the blasted solid rock fragments form a right$-$angle triangular slope at a frictional angle of repose $(\backslash$phi $).$

Question $16$Select one:

A$.$

B $=13\mathrm{.}0$ m

B$.$

B $=18\mathrm{.}5$ m

C$.$

B $=17\mathrm{.}5$ m

D$.$

B $=11\mathrm{.}0$ m

E$.$

B $=12\mathrm{.}5$ m