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Geometry Difficulty 2.4 Junior Find the answer Canada

The diagram is made up of four congruent rectangles with
dimensions 3 by 4.

Hide/Reveal Description of Diagram for Q11

The four rectangles are arranged side-by-side forming one larger
rectangle. The left side of the large rectangle is labeled 4. The top
(and bottom) is the total of four sides of length 3. A is the bottom
left vertex of the large rectangle and B is the top right corner. A path
is made up of line segments. It starts at A, moves diagonally up across
the first rectangle, down the side shared by rectangles 1 and 2, across
the bottoms of rectangles 2 and 3, up the shared side of rectangles 3
and 4, and the across the top of rectangle 4, ending at B.

What is the length of the path from $A$ to $B$ shown on the diagram?

Pick one

Solution

Since $BCD$ is a straight line segment, then $\$\angle$ BCD
$=180\degree$ $. Therefore,$ $\angle$ ACB $=\angle BCD-\angle ACD=180\degree-75\degree=105\degree$ . Since the sum of the three angles in

Figure for this problem $\triangle$ ABC $is$ $180\degree$ $, then$ $\angle ABC=180\degree-105\degree-35\degree=40\degree\$.$

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Source: CEMC, University of Waterloo, licensed CC-BY-NC-4.0. Statement reproduced verbatim; metadata (topic, difficulty) added by this project.