The sum of two straight angles is a/an ___ .
right angle
straight angle
complete angle
acute angle
Straight angle - 180∘
The sum of two straight angles is180∘+180∘=360∘, which is complete angle.
Fill in the blanks with acute, obtuse, right or straight:
(a) An angle whose measure is less than that of a right angle is _______.
(b) An angle whose measure is greater than that of a right angle is _______.
(c) An angle whose measure is the sum of the measures of two right angles is _______.
(d) When the sum of the measures of two angles is that of a right angle, then each one of them is _______.
(e) When the sum of the measures of two angles is that of a straight angle, and if one of them is acute then the other should be _______.