Advertisements
Advertisements
Question
A quadrilateral has three acute angles each measures 80°. What is the measure of the fourth angle?
Solution
\[\text{ Let x be the fourth angle } . \]
\[ \text{ Since, the sum of all angles of a quadrilateral is } 360°, \text{ we have: } \]
\[80° + 80° + 80° + x = 360° \]
\[ \Rightarrow 240° + x = 360° \]
\[ \Rightarrow x = 120° \]
\[ \therefore \text{ The fourth angle is } 120° .\]
APPEARS IN
RELATED QUESTIONS
Define the following term Quadrilateral .
In a quadrilateral, define of the following Diagonals .
In a quadrilateral, define of the following Exterior .
Complete of the following, so as to make a true statement:
The number of pairs of adjacent angles of a quadrilateral is .......
In a quadrilateral ABCD, CO and DO are the bisectors of ∠C and ∠D respectively. Prove that \[∠COD = \frac{1}{2}(∠A + ∠B) .\]
In ΔABC, E is the mid-point of median AD such that BE produced meets AC at F. IF AC = 10.5 cm, then AF =
Angle A of an isosceles trapezium ABCD is 115°; find the angles B, C and D.
Observe the figure below and find out their name.
D and E are the mid-points of the sides AB and AC respectively of ∆ABC. DE is produced to F. To prove that CF is equal and parallel to DA, we need an additional information which is ______.
A pair of opposite sides of a trapezium are ______.
