Practice problem using lambda inside the class

[jagasrik]

I am trying to check if the sum of all 3 sides of triangle is equal to 180 , if it is then it should output true else false,
I am using lamba function to implement it, as i want some practice.
This is what i tried i am getting output as

<function __main__.Triangle.check_angles.<locals>.<lambda>>

instead i should be getting True or False, i really wanna use lamba here, do let me know what i am missing, thanks a lot in advance.

My code here:

class Triangle():
    def  __init__(self, angle1, angle2, angle3):
        self.angle1=angle1 
        self.angle2=angle2
        self.angle3=angle3
        self.number_of_sides=3
    
    def check_angles(self):
        return (lambda self:'True' if (self.angle1+self.angle2+self.angle3)==180 else 'False')

cal=Triangle(45,45,90)
cal.check_angles()