Question

$△$DEF is drawn with the length of side EF being 7.5 cm. If $\angle$E is 75${}^{\circ }$ and $\angle$F is 55${}^{\circ }$, then the measure of $\angle$D is

• A. 40${}^{\circ }$
• B. 30${}^{\circ }$
• C. 50${}^{\circ }$
• D. 20${}^{\circ }$

Answer 1

The correct option is C

50${}^{\circ }$

Steps of construction of $△$DEF:

Step 1:
Draw the base line EF of the length 7.5 cm.

Step 2:
Measure the angle E with your protractor. Make a mark at 75 degrees and draw a line from E passing through the mark.

Step 3:
Measure the angle F with your protractor. Make a mark at 55 degrees and draw a line from F passing through the mark.

Step 4:
Name the point of intersection of these two lines as D and the $△$DEF is complete, as shown below.

Now, from the above construction the measure of $\angle$D is 50${}^{\circ }$.