Section 7.3 Triangles 287 Tell whether x and y show direct variation. Explain your reasoning. If so, fi nd the constant of proportionality. (Section…

Section 7.3 Triangles287Tell whether x and y show direct variation. Explain your reasoning.If so, fi nd the constant of proportionality.(Section 5.6)28.x = 2y29.y − x = 630.xy = 531.MULTIPLE CHOICE A savings account earns 6% simple interest per year. Theprincipal is $800. What is the balance after 18 months?(Section 6.7)○A$864○B$872○C$1664○D$7200Draw a triangle with the given angle measures. Then classify the triangle.14.15°, 75°, 90°15.20°, 60°, 100°16.30°, 30°, 120°Draw a triangle with the given description.17.a triangle with a 2-inch side and a 3-inch side that meet at a 40° angle18.a triangle with a 45° angle connected to a 60° angle by an 8-centimeter side19.an acute scalene triangle20. LOGIC You are constructing a triangle. You draw9090801007011060120501304014030150201601017001801008011070120601305014040150301602017010180035íthe fi rst angle, as shown. Your friend says that youmust be constructing an acute triangle. Is yourfriend correct? Explain your reasoning.Determine whether you can construct many, one, or no triangle(s)with the given description. Explain your reasoning.21.a triangle with angle measures of 50°, 70°, and 100°22.a triangle with one angle measure of 60° and one 4-centimeter side23.a scalene triangle with a 3-centimeter side and a 7-centimeter side24.an isosceles triangle with two 4-inch sides that meet at an 80° angle25.an isosceles triangle with two 2-inch sides and one 5-inch side26.a right triangle with three congruent sides27.Consider the three isosceles triangles.xí50í65í130í25íxí45íxía.Find the value of x for each triangle.b.What do you notice about the angle measures of each triangle?c.Write a rule about the angle measures of an isosceles triangle.2233mms_red pe_0703.indd 287s_red pe_0703.indd 28722/2/15 8:25:40 AM/2/15 8:25:40 AM