A f lying buttress transmits a load $25$kNP$5,$ acting at an angle of $608$ to the horizontal, to the top of a vertical buttress AB $($see gure$).$ The vertical buttress has height $5\mathrm{.}0$mh$5$ and rectangular cross section of thickness $1\mathrm{.}5$mt$5$ and width $1\mathrm{.}0$m