🔍 Key Concepts

• Engineering drawing conventions for holes (how through vs blind holes are shown with visible and hidden lines) • Meaning of a radius (R) dimension on a circular feature and how to get the diameter • Difference between a blind hole and a fully bored (through) hole

💭 Think About

• Look closely at the dashed lines and circles: do they show the hole stopping inside the material, or continuing all the way through the block? • If the radius of the hole is given as 3/4 R, what is the full diameter, and which choice matches that value? • Ask yourself which option describes both the depth/extent of the hole and the size indicated in the drawing.

✅ Before You Answer

• Verify whether the hidden (dashed) circle appears on the bottom surface of the block, which would indicate a through hole. • Check that the diameter you compute from the 3/4 R dimension agrees with one (and only one) of the answer choices. • Confirm whether any depth dimension is actually labeled for the hole; if none is shown, be cautious about answers that specify a precise hole depth.