Q. 7 A

ABC DEF is a similarity in ΔABC and ΔADEF, mA = 40, mE + mF =
A. 40

B. 80

C. 140

D. 180

Answer :

Given: m A = 40°


The correspondence ABC DEF is a similarity between ∆ABC and ∆DEF.


To find: m E + m F = ?


Now by definition, for a given correspondence between the vertices of two triangles, if the corresponding angles of the triangles are congruent and the lengths of the corresponding sides are in proportion, then the given correspondence is a similarity between two triangles.


m A = m D


m A = m D = 40°


m D = 40°


In ∆DEF,


m D + m E + m F = 180°


40° + m E + m F = 180°


m E + m F = 180° - 40°


m E + m F = 140°


Answer is 140.


Thus, option (c) is correct.

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Basic Proportionality Theorem42 mins
Quiz | Criterion of Similarity of Triangle45 mins
Champ Quiz | Thales Theorem49 mins
NCERT | Strong Your Basics of Triangles39 mins
RD Sharma | Imp. Qs From Triangles41 mins
R.D Sharma | Solve Exercise -4.2 and 4.3FREE Class
How to Ace Maths in NTSE 2020?36 mins
R.D Sharma | Solve Exercise-4.545 mins
NCERT | Basic Proportionality Theorem22 mins
RD Sharma | Imp Qs Discussion- Triangles43 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
view all courses
RELATED QUESTIONS :