C.21
5^2-4=21
Explanation
8+11 is 19
Hope it helped
Answer is a right triangle. The angles of a triangle must add to 180 degrees.
You have two 45 degree angles
45 + 45= 90
Now you need 1 more angle to equal 180
180- 90= 90
A right angle is 90 degrees. A right triangle has one right angle and two acute.
area of rectangle= length × width
= 19×33
= 627 sq units
