Geometry: Geometry of a Triangle

think iconThink & Click: Similar Triangles

Now, you try. Complete the Think & Click activity by looking at each problem below, thinking about it, and then clicking on the question to reveal the solution.

Triangle ABC is similar to triangle JKC.

triangle ABC and triangle JKC

Side AB measures 25, side BC measures 15, side JK measure 30 and side KC measures
4x – 5. Find the value of x.
 

AB divided by KJ equals BC divided by KC, 25 divided by 30 equals 15 divided by the quantity 4 x minus 5, 100 x minus 125 equals 450, 100 x equals 575, x equals 5.75
 

Angle A measures (5y + 5)°, angle B measures (7y + 6)°, angle JCK measures 85 degrees. Find the value of y.
 

Since the triangles are similar, angle ACB and angle JCK have equal measure.

(5y + 5) + (7y + 6) + (85) = 180
12y + 96 = 180
12y = 84

y = 7