A) 60° B) 85° C) 96° D) 40°​

A)60°

Step-by-step explanation:

a straight line is 180° then

if a line bisect it in to a half it become 90°

then

the exterior angle of a triangle is equal to the sum of two interior angles

this means 150°-90°=60°

A) 60

Step-by-step explanation:

The line at the top signifies 180 degrees, as does any straight line. The 150° that intersects with P tells you that P must be 30 degrees, as 180 - 150 = 30.

The three angles of a triangle must always equal 180°. Angle R tells you that it’s 90°, shown by the square instead of a curve. If you subtract the value of P we found before, and the value of R we just found, you get your answer.

180 - 30 - 90 = 60.

12cm

the answer is d