Question

186
Mathematics for Class 7
On adding the corresponding sides of u). (1) and (11), we get
4 + 12 + L3=2(ZA + B + 2C)
=2x180
sum of the angles of a triangle is 1801
=360
1 2+13=355
Hence, the sum of the exterior angles is 360°
EXERCISE 15B
75
1. In the figure given alongside, find the measure of ZACD.
2. In the figure given alongside, find the values of x and y.
3. In the figure given alongside, find the values of x and y.​

Answer 1

Answer:The measures of two angles of a triangle are 72° and 58°.

Let the third angle be x.

Now, the sum of the measures of all the angles of a triangle is 180o​.

∴ x + 72o + 58o = 180o

⇒ x + 130o = 180o

⇒ x = 180o​ − 130o

⇒ x = 50o

​The measure of the third angle of the triangle is 50o​.

Step-by-step explanation: