Question 22
A tent has front and back widths 4 m and two side widths 3 m. It consists of six vertical poles and waterproof tarpaulin, as shown. Poles $AF$ and $OC$ are 2.2 m long; the other four poles are 1.7 m long. The “top horizontal bar” $IF$ is 3 m long. The angle between this “top horizontal bar” and the tarpaulin plane $(CDEF)$ is $a^\circ$, rounded to the nearest integer. Find $a$.
The following source mathematical images preserve the printed option/formula/figure variants; text and choices above or below provide clean typesetting.
The following source mathematical images preserve the printed option/formula/figure variants; text and choices above or below provide clean typesetting.