● Isosceles Triangle ORQ is also Right Triangle ORQ
● m∠ORQ = 90°
● m∠ROQ = m∠RQO < 90°
Another example of how a triangle can fall into two classification groups
is illustrated in the following triangle, ΔKJO. ∠J is an obtuse angle and
∠O = ∠K, which makes ΔKJO an isosceles triangle and an obtuse trian-
gle. It can be said that ΔKJO is an obtuse isosceles triangle.
● Obtuse Isosceles Triangle JKO
● m∠OJK > 90°
● m∠JKO and m∠KOJ < 90°
25 °
130 ° 25 °
K
J O
leg
leg
hypotenuse
45 °
45 °
R Q
O
501 Geometry Questions