Guided Practice #1
Practice Problem #1
Find the missing angle measures.
Remember, the consecutive angles in a trapezoid are supplementary.
Which angle is consecutive to ∠D?
Answer: ∠A
Which angle is consecutive to ∠C?
Answer: ∠B
Ok, let's solve for A first. Since A and D form a consecutive angle pair, they are supplementary. So,
∠A + ∠D = ___°
Answer: 180°
Substitute in the measure of ∠D.
∠A + ___° = 180°
Answer: 90°
Isolate the unknown value to solve.
∠A = ___°
Answer: 90°
Great! Now, let's solve for B. Since B and C form a consecutive angle pair, they are supplemntary. So:
∠B + ∠C = 180°
Substitute in the measure of C.
∠B + ___° = 180°
Answer: 112°
Isolate the unknown value to solve.
∠B = ___°
Answer: 68°
Practice Problem #2
Find the missing angle measures.
Remember, the consecutive angles in a trapezoid are supplementary.
Which angle is consecutive to ∠D? ∠___
Answer: ∠A
What about ∠B? ∠___
Answer: ∠C
Ok, let's solve for A first. Since A and D form a consecutive angle pair, they are supplementary. So,
∠A + ∠D = ___°
Answer: 180°
Substitute in the measure of ∠D.
∠A + ___° = 180°
Answer: 90°
Isolate the unknown value to solve.
∠A = ___°
Answer: 90°
Great! Now, let's solve for C. Since B and C form a consecutive angle pair, they are supplementary. So, ∠B + ∠C = 180°
Substitute in the measure of ∠B.
___° + ∠C = 180°
Answer: 132°
Isolate the unknown value to solve.
∠C = ___°
Answer: 48°
