# <span lang="EN-US

BC = CD

AC which is common to both ∆ADC and ∆ABC.

So, DAC = CAB = 30 as AB = AD and AC which is common.

And, DCA = ACB = 50 as BC = CD and AC which is common.

Now, we know sum of all interior angles of a triangle is 180⁰.

a + d + c = 180⁰

30⁰ + d + 50⁰ = 180

80⁰ + d = 180⁰

d = 180⁰-80⁰

d = 100⁰

In ∆ABC,

a + b + c = 180⁰

30⁰ + b + 50⁰ = 180⁰

80⁰ + b = 180⁰

b = 180⁰-80⁰

b = 100⁰

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
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 :

<span lang="EN-USKerala Board Mathematics Part I

<span lang="EN-USKerala Board Mathematics Part I

<span lang="EN-USKerala Board Mathematics Part I

<span lang="EN-USKerala Board Mathematics Part I

<span lang="EN-USKerala Board Mathematics Part I

<span lang="EN-USKerala Board Mathematics Part I

<span lang="EN-USKerala Board Mathematics Part I

<span lang="EN-USKerala Board Mathematics Part I