Answer:
A) Right Angle Triangle
B) 25 units²
C) (15 + 5√5) units
Figure Their Length:

Distance between C and A

Distance between C and T

Distance between A and T

Part A:
When drawn on graph, we can identify it is a right angle triangle.
Or use Pythagoras Theorem:
10² + 5² = (5√5)²
125 = 125... Hence it is a right angle triangle confirmed.
Part B:
Area of triangle = ½ × base × height = ½ × 10 × 5 = 25 units²
Part C:
Total Sum or measure of all sides: 5 + 10 + 5√5 = 15 + 5√5 units