Harry is using a total of 34 feet of lumber to make a bookcase. The left and right sides of the bookcase are each 5 feet high. The top, bottom, and two shelves are all the same length, labeled w. How long is each shelf?

The most frequently used quality materials for custom-built wood shelves are 3/4” thick plywood, poplar, or pine; definitely avoid the melamine-laminated composite shelving and MDF.

Step-by-step explanation:

∠acb = 8°

step-by-step explanation:

∠xba lies on the circle and is half the measure of the intercepted arc ax

hence

measure of arc ax = 2 × 42° = 84°

∠acb is outside the circle and is

∠acb = (arcab - arcax ), hence

∠acb = 0.5 (100 - 84) = 0.5 × 16° = 8°