Answer:
Step-by-step explanation:
Let <ADB be x. From the rectangle, <ADB+<BDC = <ADC
<ADB+<BDC = 90° ..... 1
If angle BDC is 31° greater than mangle ADB, then <BDC = x+31
Substituting the given values into the equation 1:
x+x+31 = 90
2x + 31 = 90
2x = 90-31
2x = 59
x = 59/2
x = 29.5°
To get <BDC, we will substitute x = 29.5° into the expression <BDC = x+31
<BDC = 29.5+31
<BDC = 60.5°
Hence <ADB = 29.5° and <BDC = 60.5°