I think it’s C
Explanation: the blue yarn is 7 and the red yarn is 10 if you combine both as 7 + 10= 17
If you're talking about number 18 its the first option <span />
<h2>Given</h2>
- A quadrilateral ABCD with opposite pairs of sides being congruent.
<h2>To prove</h2>
- Opposite sides are parallel.
<h2>Solution</h2>
We'll prove first the triangles formed by diagonal are congruent then we'll prove the angles on either side of diagonal are congruent.
<u>The steps are:</u>
- Step ⇒ Statement ⇒ Reason
=============================================================
- 1 ⇒ AB ≅ CD and BC ≅ AD ⇒ Given
- 2 ⇒ AC = CA ⇒ Common side
- 3 ⇒ ΔABC ≅ ΔCDA ⇒ Side-side-side congruence
- 4 ⇒ ∠BAC ≅ ∠DCA ⇒ Corresponding angles of congruent triangles
- 5 ⇒ ∠BAC and ∠DCA are alternate interior angles ⇒ Definition of alternate interior angles
- 6 ⇒ AB║CD ⇒ The converse of alternate interior angles theorem
- 7 ⇒ ∠BCA ≅ ∠DAC ⇒ Corresponding angles of congruent triangles
- 8 ⇒ ∠BCA & ∠DAC are alternate interior angles ⇒ Definition of alternate interior angles
- 9 ⇒ BC║AD ⇒ The converse of alternate interior angles theorem
