p. 246-247: 11-18
11. Plug in the value of y to the 3 expressions. Be careful about your order of operations (PEMDAS). The (10y^2) is for angle M (the top angle). Once you have all of the values, identify the structure, and you should be able to justify that the triangles are congruent. Create a valid congruence statement (order of the letters matter)
12. Similare to 11.
13. In the given, AB (upside down T) DC means that AB is perpendicular to DC. Recall: Definition of Perpendicular- two lines are perpendicular if and only if they intersect at right angles.
14-17- Don’t forget about shared sides, and vertical angles. Also, two of the problems do not have enough information to conclude the two triangles are congruent.
18 Even though it only looks like one pair of parts are congruent, there is a second thing given on the diagram. You need to identify the extra piece or pieces of info needed that would allow you to use: a.) SSS or b.) SAS given what you have so far on the diagram.