4 sides. Think of a trapezoid like a drunk rectangle.
-Hope this helps!
The height of plant y =x+25
Remark: What might be confusing you is the the given expression must add up to 90o. You know this because <B = 90 so the other two angles must be 90o.
Equation
5x - 10 + 6x - 21 = 90 Combine like terms on the left
11x - 31 = 90 Add 31 to both sides.
11x - 31 + 31 = 90 + 31
11x = 121 Divide by 11
x = 121/11 = 11.
Find the value of 6x - 21
6*11 - 21 = 66 - 21= 45
Comment
The central angle for arc AB (which is double ADB = 2*45 =90) is 90. So arc AB = 90
