Can somebody help me?

Part (a)

Step-by-step Explanation:

As ∠K is  a right angle.

i.e.

also

Equation to find x

As we know that The angle sum of a Triangle is 180°.

so

m∠K + m∠L + m∠M = 180°

Part (b)

Step-by-step Explanation:

Finding the degree measures of each angle.

As

As ∠K is  a right angle.

so

Putting in m∠L = (2x+19)°

m∠L = (2x+19)°

         =

so

m∠L = 39.8°

Putting in m∠M = (3x+21)°

m∠M = (3x+21)°

so

m∠M = 50.2°

Verification:

m∠K + m∠L + m∠M = 180°

 90°  + 39.8° + 50.2° = 180°

 90° + 90° = 180°          ∵ 39.8° + 50.2° = 90°

 180° = 180°

answer: -1

step-by-step explanation: