Question

Question 2(Multiple Choice Worth 4 points)

(05.09A MC)

What is the measure of angle CED?

There are two triangles labeled ABC and DCE with a common vertex C. In triangle ABC, angle BAC is labeled as p, and angle ABC is labeled as 70 degrees. In triangle DCE, angle CDE is labeled as 70 degrees.

p over 2, because Triangle ABC is congruent to triangle DCE
p + 70 degrees, because Triangle ABC is similar to triangle DCE
110 degrees − p, because Triangle ABC is congruent to triangle DCE
p, because Triangle ABC is similar to triangle EDC

Answer 1

p, because Triangle ABC is similar to triangle EDC

Explanation:

Answer 2

• p, because Triangle ABC is similar to triangle EDC

Explanation:

Given

• The triangles have a common vertex C
• m∠ABC = 70°
• m∠BAC = p
• m∠CDE = 70°
• m∠CED = ?

Solution

As C is common vertex, the angles BCA and DCE are vertical angles and therefore have same measure

Sum of angles of ABCΔ:

• 70° + p + ∠C = 180°

Sum of angles of ΔEDC:

• 70° + ∠CED + ∠C = 180°

Comparing the sums above we get:

• ∠CED = p

Correct option is the last one:

• p, because Triangle ABC is similar to triangle EDC