Page 150 - Math Smart - 7
P. 150
^ ABC\s an isosceles triangle and ^BAC= 82°.
/^ACB = /.ABC because
triangle ABC has a line of Find ^ABC
symmetry, AD.
Solution
A
^ACB=^ABC
= (180°-82°)-r2
= 49°
0 ABC is an equilateral triangle and ^AED = 85'
An isosceles triangle has
Find ^ADE.
two equal angles and two
equal sides. The angles Solution
opposite the equal sides ^EAD = eO°
are equal. They are called AADE= 180°-60°-85°
the base angles of the
= 35°
triangles.
O IVXris an isosceles triangle. Angle X is a right angle and = 86°.
Find ZZXK
Solution
ZlVXT=90°
zxwr=zxw
= 90° ^ 2
= 45°
In triangle H/XZ, ZlVXZ= 180°-45°-86'=
= 49°
ZZXy= 90°-49°
= 41°
Check My
Understanding
O In triangle KLM, /.KLM = 15° and AKML = 27° Q In triangle PQR, ZPfiQ = 65° and ZQP/? is a right
Find Z.LKM. angle. Find /.PQR.
P
E UNIT 6 Angles and Their Properties
