Respuesta :

A is 100 degree.

Angle QRP= 180 degree - 140 degree = 40 degree

PQ=RQ so the triangle is a isoceles triangle.
Hence, angle b is also 40 degree.

Angle a = 180 deg - 40 deg- 40 deg = 100 degree
SJ2006

a = 90 degrees

As it is a characteristics of right isosceles triangle.....