Answer:
The perimeter of the kite JKLM is 50 units ⇒ C
Step-by-step explanation:
The longest diagonal of the kite is its axis of symmetry which means the longest diagonal divides the kite into two congruent triangles
∵ JKLM is a kite
∵ KM is the longest diagonal
∴ KM is divides the kite into two congruent triangles
∴ Δ JKM is congruent to Δ LKM
∴ JK = LK
∴ JM = ML
∵ ML = 10 units
∴ JM = 10 units
∵ The diagonals of the kite are perpendicular
∴ KM ⊥ JL
∵ KM and JL intersected at N
∴ m∠JNK = 90°
∵ KM is the axis of symmetry of kite JKLM
∴ KM bisects JL at N
∴ JN = NL = JL
∵ JL = 18 units
∴ JN = (18)
∴ JN = 9 units
In Δ JNK
∵ m∠JNK = 90°
∵ JN = 9 units
∵ NK = 12 units
- By using Pythagoras Theorem
∵ (JK)² = (JN)² + (NK)²
∴ (JK)² = (9)² + (12)²
∴ (JK)² = 81 + 144
∴ (JK)² = 225
- Take √ for both sides
∴ JK = 15 units
∵ Jk = LK
∴ Lk = 15 units
∵ The perimeter of the kite is the sum of its 4 sides
∴ P = JK + KL + LM + MJ
∵ JK = LK = 15
∵ JM = ML = 10
∴ P = 15 + 15 + 10 + 10
∴ P = 50
The perimeter of the kite JKLM is 50 units