Q51 of 153 Page 148

The sides BC, BA and CA of ΔABC have been produced to D, E and F respectively, as shown in the given figure. Then, ∠B = ?

BAC = 35^o (opposite pair of angles)

BCD = 180 – 110 = 70^o (linear pair of angles)

Now, in Triangle ABC we have,

A + B + C = 180^o

35 + B + 70 = 180

B = 180 – 105 = 75^o

The angles of a triangle are in the ratio 3:5:7. The triangle is

If the vertical angle of a triangle is 130°, then the angle between the bisectors of the base angles of the triangle is

In the adjoining figure, y = ?

Each question consists of two statements, namely, Assertion (A) and Reason (R). Choose the correct option.

Assertion (A)	Reason (R)
If the two angles of a triangle measure 50° and 70°, then its third angle is 60°.	The sum of the angles of a triangle is 180°.