To find the missing angles in the quadrilaterals, we use the rule that all four angles inside a quadrilateral add up to
360°.
We will solve for the missing angle in each shape by adding the three known angles and subtracting that total from 360.
1. Green Quadrilateral (Top Left)
* Known angles: $G = 75^\circ$, $H = 105^\circ$, $J = 95^\circ$
* Missing angle: $I$
* Step 1: Add the known angles: $75 + 105 + 95 = 275$
* Step 2: Subtract from 360: $360 - 275 = 85$
* So,
$I = 85^\circ$
2. Pink Quadrilateral (Top Right)
* Known angles: $A = 90^\circ$, $B = 78^\circ$, $D = 55^\circ$
* Missing angle: $C$
* Step 1: Add the known angles: $90 + 78 + 55 = 223$
* Step 2: Subtract from 360: $360 - 223 = 137$
* So,
$C = 137^\circ$
3. Light Green Quadrilateral (Middle)
* Known angles: $V = 100^\circ$, $W = 94^\circ$, $X = 81^\circ$
* Missing angle: $U$
* Step 1: Add the known angles: $100 + 94 + 81 = 275$
* Step 2: Subtract from 360: $360 - 275 = 85$
* So,
$U = 85^\circ$
4. Purple Quadrilateral (Bottom)
* Known angles: $Q = 82^\circ$, $R = 77^\circ$, $S = 88^\circ$
* Missing angle: $P$
* Step 1: Add the known angles: $82 + 77 + 88 = 247$
* Step 2: Subtract from 360: $360 - 247 = 113$
* So,
$P = 113^\circ$
Final Answer:
I = 85°
C = 137°
U = 85°
P = 113°
Parent Tip: Review the logic above to help your child master the concept of quadrilateral angle worksheet.
