**Master Purushottam**

Let the first and second angle be a and b respectively

Third angle = a+b

By angle sum property of triangle

a +b + a+b = 180

=> 2a +2b = 180

=> 2(a+b) = 180

=> a+b = 90°

Third angle = 90°

*-Answered by Master Purushottam* On 23 August 2019:11:41:59 PM