JKLM is a square. DCL and KCM are straight lines. KJ = KD and ∠CKD = 13°. Find
- ∠KJD
- ∠MLD
.
(a)
∠JKM = 45° (Right angle)
∠JKD
= ∠JKM - ∠CKD
= 45° - 13°
= 32°
∠KJD
= (180° - ∠JKD) ÷ 2
= (180° - 32°) ÷ 2
= 148° ÷ 2
= 74° (Isosceles triangle)
(b)
KJ = KD = KL
DKL is an isosceles triangle.
∠KDL = ∠KLD (Isosceles triangle)
∠KLD
= (180° - ∠MKL - ∠CKD) ÷ 2
= (180° - 45° -13°) ÷ 2
= 122° ÷ 2
= 61°
∠MLD
= ∠KLM - ∠KLD
= 90° - 61°
= 29°
Answer(s): (a) 74°; (b) 29°
