English

In a triangle ABC, the measure of angle A is 40° less than the measure of angle B and 50° less than that of angle C. Find the measure of ∠A. - Mathematics

Advertisements
Advertisements

Question

In a triangle ABC, the measure of angle A is 40° less than the measure of angle B and 50° less than that of angle C. Find the measure of ∠A.

Sum

Solution

According to the question,

Measure of ∠A = ∠B = 40°

Measure of ∠C = ∠B – 40° + 50°

We know that, the sum of all three angles in a triangle is equal to 180°

i.e. ∠A + ∠B +  = 180°°

⇒ (∠B – 40°) + ∠B + (∠B – 40° + 50°) = 180°

⇒ 3∠B – 30° = 180°

⇒ 3∠B = 210°

∴ ∠B = `210^circ/3` = 70°

So, the measure of ∠A = 70° – 40° = 30°.

shaalaa.com
  Is there an error in this question or solution?
Chapter 6: Triangles - Exercise [Page 172]

APPEARS IN

NCERT Exemplar Mathematics [English] Class 7
Chapter 6 Triangles
Exercise | Q 111. | Page 172

Video TutorialsVIEW ALL [1]

Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×