Advertisements
Advertisements
Question
In the given figure, what is z in terms of x and y?

Options
x + y + 180
x + y − 180
180° − (x + y)
x + y + 360°
Advertisements
Solution
In the given ΔABC, we need to convert z in terms of x and y

Now, BC is a straight line, so using the property, “angles forming a linear pair are supplementary”
∠ABC + y = 180
∠ABC =180° - y°
Similarly,
∠ACB + x° = 180°
∠ACB = 180° - x
Also, using the property, “vertically opposite angles are equal”, we get,
z = ∠BAC
Further, using angle sum property of the triangle
∠BAC + ∠ABC + ∠ACB = 180°
z° + (180°- y°) + (180° - x°) = 180°
360° + z° - y° - x° = 180°
180° + z° = y° + x°
z° = y°+ x° -180°
Thus, z = y + x -180°
APPEARS IN
RELATED QUESTIONS
Find the measure of each exterior angle of an equilateral triangle.
In Fig. 10.40, it is given that RT = TS, ∠1 = 2∠2 and ∠4 = 2∠3. Prove that ΔRBT ≅ ΔSAT
Prove that the medians of an equilateral triangle are equal.
In an isosceles triangle, if the vertex angle is twice the sum of the base angles, calculate the angles of the triangle.
Angles A, B, C of a triangle ABC are equal to each other. Prove that ΔABC is equilateral.
Which of the following statements are true (T) and which are false (F) :
If the altitude from one vertex of a triangle bisects the opposite side, then the triangle may be isosceles.
Which of the following statements are true (T) and which are false (F):
The two altitudes corresponding to two equal sides of a triangle need not be equal.
Fill the blank in the following so that the following statement is true.
In a ΔABC if ∠A = ∠C , then AB = ......
O is any point in the interior of ΔABC. Prove that
(i) AB + AC > OB + OC
(ii) AB + BC + CA > OA + QB + OC
(iii) OA + OB + OC >` 1/2`(AB + BC + CA)
Prove that the perimeter of a triangle is greater than the sum of its altitudes.
Which of the following statements are true (T) and which are false (F)?
Sum of any two sides of a triangle is greater than the third side.
Fill in the blank to make the following statement true.
The sum of three altitudes of a triangle is ..... than its perimeter.
In a ΔABC, if ∠A = 60°, ∠B = 80° and the bisectors of ∠B and ∠C meet at O, then ∠BOC =
If the measures of angles of a triangle are in the ratio of 3 : 4 : 5, what is the measure of the smallest angle of the triangle?
In the given figure, what is the value of x?

The side BC of ΔABC is produced to a point D. The bisector of ∠A meets side BC in L. If ∠ABC = 30° and ∠ACD = 115°, then ∠ALC = ______.
Which of the following correctly describes the given triangle?
In ∆PQR, ∠R = ∠P and QR = 4 cm and PR = 5 cm. Then the length of PQ is ______.
In the following figure, D and E are points on side BC of a ∆ABC such that BD = CE and AD = AE. Show that ∆ABD ≅ ∆ACE.

Find all the angles of an equilateral triangle.
