In the figure AC=CD,AD=BD and angle C=58° find ANGLE CAB
Answers
see the attachment!
Answer:
91.5° is the required value of ∠CAB
Step-by-step explanation:
Explanation:
Given , ABC is a triangle in which
AC = CD , AD = BD and ∠C = 58°.
Therefore , AC = CD and AD = BD
So , know that if two sides of a triangle are equal, then the angles opposite those sides are equal
⇒∠CAD = ∠CDA and ∠ BAD = ∠DAB
Let ∠CAD = ∠CDA be x and
Let ∠ BAD = ∠DAB be y
Step 1:
In ΔACD , ∠ACD = 58° given
∠CAD + ∠CDA +∠ACD = 180 [sum of angle of triangle is 180 ]
⇒x + x + 58 = 180
⇒2x = 180- 58 = 122
⇒x = = 61
Therefore , ∠CAD = ∠CDA = 61 °
And ∠ ADC + ∠ADB = 180 [Linear pair]
⇒ 61 + ∠ADB = 180 [∠CDA =∠ADC = 61 ]
⇒∠ADB = 180 -61 = 119
Step 2:
In Δ ADB ,∠ADB = 119 .
∠ADB +∠ABD +∠DAB = 180 [Sum of angle of triangle is 180°]
⇒119 + y + y = 180
⇒119 + 2y = 180
⇒y = = 30.5°
Therefore , ∠ BAD = ∠DAB = 30.5°
Step 3:
From step 1 and step 2 we get ,
∠ CAD = 61 °and ∠BAD = 30.5°
Therefore, ∠CAB = ∠ CAD + ∠BAD
⇒ ∠CAB = 61 + 30.5 = 91.5°
Final answer:
Hence , the angle of ∠CAB is 91.5°.
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